Build the web pages before the app: how a underwater spearfishing forecast ranked #5,800 in Portuguese and Greek search
What it is A sea-condition forecast for spearfishers and freedivers: it tells you whether a stretch of coast is diveable today and roughly how many meters of visibility you'll have underwater. The web version is free; the app sells subscriptions.
Why it's taking off It first shipped city forecast pages covering 85 countries in 9 languages, and ranked ahead in Portuguese, Greek and Spanish search, where the big English platforms weren't bothering. Add a free shout-out from Australia's biggest spearfishing podcast and a plugin that drives traffic from Windy.
BHow you could copy it Don't copy the spearfishing niche itself, copy the template: pick outdoor activities like surfing, rock fishing, foraging on the shore or paddleboarding, where people currently juggle several apps before heading out. Use public weather and ocean data to compute a go/no-go verdict, build one page per city per language to catch non-English search, then sell subscriptions in the app.
- Data (updated daily) · launched 2026-07-10 · US store rating 9 · charted in 11-08 of 72 stores
iOS · best category chart rank · by store US storeUKAustraliaData 2026-10-28 → 2026-11-08 (12 days, 12 observations). Lower rank is higher; gaps mean it wasn't charted that dayiOS · rating count · US store Data 2026-10-28 → 2026-11-08 (12 days, 12 observations). Apple doesn't publish download counts; rating growth is a proxy for downloads.
Spearo (spearo.app) answers the question spearfishers most want answered before leaving home: can I see underwater today? It combines waves, wind, tides, rain, water temperature and satellite water color into a 0–10 score and a red/yellow/green verdict, plus an estimated visibility of a few meters. Launched on iOS in July; it has 138 ratings on iOS and about 38k installs on Android, so it's not big. What's worth watching is the approach: before the app launched, the website covered 9 languages and roughly 5,800 city pages, capturing small-language search traffic that the big English platforms ignored.
Sep 2, episode one, second 80
In Sep 2 2026, the Australian spearfishing podcast Noob Spearo released its episode 321. At minute 1 and second 20 of the opening, host Shrek slipped in a plug: the show notes read "Free shout out to Spearo App, a completely free spearfishing forecasting app, and the level of detail that gobsmacked Shrek." The previous episode (from Aug 24, episode 320) had already linked it in the notes. The host calls it a "free shout out," not a sponsorship.
The numbers that line up: Australia has 10 ratings and New Zealand 8, and in New Zealand it ranked #8 in the free Weather chart on the App Store (11-06).
But the podcast is icing. The countries with the most ratings are Portugal (19), France (18), Turkey (16), Brazil (12), Greece (11) and Spain (11), while the US has only 9. An app with an English name, its main market is small Southern European languages. The reason lies in its website.
What it is
Open spearo.app and the first line is "When to dive — the answer in one second." Below it is a dial: today's score is 5.3, waves 0.3 m, visibility about 9 m, labeled "Marginal," and further down are the next 7 days' scores and a "Remind me when it turns green" button.
The verdict is computed from seven factors: swell (it "remembers" storms from the previous days), wind and gusts, tides, water temperature, currents, rainwater runoff, and the coast's orientation. There are also hard gates: thunderstorms prevent a green rating, an official warning downgrades it, and when several forecast models disagree sharply, green is pulled back to yellow. Where night spearfishing is illegal, nights are always marked red. Each city page also carries the entry-point coordinates, a no-take zone map and local regulations.
Payment happens in the app: free users see the next few days, can save 3 spots and get alerts for 1 locations; Pro unlocks the full 7 days, 5 spots and more alerts; Ultra covers 10 spots. The annual Pro plan comes with a 7-day trial (Google Play store page, 11-06). One US review complains "it asks for a $43 subscription right away."
It's run by one person or a very small team: the Apple developer account is Diana Dryn, and the website's legal entity is dryn.dev (Łukasz Dryński), a sole proprietorship in Warsaw, Poland, which previously ran small sites such as a Polish event calendar. The data starting point the site names, "home coast," is in Portugal (inferred, not verified). Iteration is very fast: the iOS version went from 1.3.24 in Oct 20 to 1.3.37 in Nov 5, with 14 releases in two weeks, and coverage expanded from 26 countries in July to 85 today.
How big it is
| Metric | Sources | |
|---|---|---|
| iOS ratings | 123(10-28) → 138(11-06), +12 in a week | App Store |
| iOS charts | Charted in the Weather category in 62–73 countries; best Top Grossing ranks: #8 in Oman, #9 in Greece, #9 in Cyprus, #19 in Portugal | App Store, 10-28 to 11-06 |
| Android installs | 34,945 (10-29) → 37,838 (11-06), about 360 per day; back in August it was only 5,000+ | Google Play;AppBrain |
| Android ratings | 235 | Google Play |
Android is the main market, roughly ten times iOS by rating count (a rough estimate). Treat the iOS chart positions with a grain of salt: in the Weather Top Grossing charts in Greece, Cyprus and Oman, a few subscriptions can put you in the top 10, and the number of paying users may only be dozens to hundreds (inferred).
Where users come from: the website launched first, the app later
Multilingual city pages (main channel). The spearo.app sitemap has about 5,800 pages in 9 languages: English 3,387, Spanish 517, French 425, Portuguese 359, Italian 244, Greek 229, Russian 209, Croatian 207, Turkish 201 (11-06 actually crawled). Every coastal city has a forecast page, and every country has a regulations and seasonal guide, such as the Greek "Ψαροντούφεκο στην Ελλάδα" or the Spanish "Pesca submarina en España: licencia por comunidad…"
A live search (Brave, 11-06): for the Portuguese "previsão pesca submarina," it ranks #1 and #2; for the Greek "πρόγνωση ψαροντούφεκο ορατότητα," #1 and #2 are both it; for the English "spearfishing forecast" it's #2; for the Spanish "previsión pesca submarina visibilidad" it's #4.
The order is clear: the guide pages were indexed by search engines on July 5 and 6, while the app only launched on July 10. The app store description opens with "Spearo (spearo.app)," and the store links carry utm_source=organic. Its robots.txt also explicitly allows ChatGPT's crawler, so it's building for AI search too. The languages with the most ratings are exactly the ones it covers.
Piggybacking on Windy. In Sep 21 it published an "Official spearo.app plugin" on GitHub for Windy.com, one of the world's largest wind and wave forecast sites; searching Windy's plugin list turns up "Water visibility forecast … Data by spearo.app." The plugin shows only 3 days; for the full 7 days you have to click back to spearo.app. How much traffic that brings isn't visible from outside.
Niche podcasts. The two Noob Spearo episodes mentioned at the start.
Paid acquisition: not seen. It doesn't appear in the Meta ad library, there's no official TikTok account or creator videos, and X search turns up nothing. However, the Android store links carry AppsFlyer attribution parameters, so the tool is installed and paid campaigns may come later.
Retention features in the app. Home-screen and lock-screen widgets, a daily morning summary push, the "turn green" alert, the "invite friends" feature added in October, and payment-failure reminders and personalized offers added in November.
Why this one
This need has been asked on Reddit's r/Spearfishing for years: "Is there an app that forecasts underwater visibility?" The answer has always been "No, piece it together yourself from WillyWeather and Windguru." Its store copy is written right at that pain point: "Most of us check three or four apps before a dive… Then we drive to the beach and find murky water anyway."
It also lays out its methodology: the /science page explains the use of Sentinel-2 satellite bathymetry, Copernicus seawater transparency data and buoys in 9 countries, with a validation error of 2.25 m, and it marks places without coverage as "no coverage" rather than guessing. The podcast host was won over by exactly these details.
But be clear about it: it wins on distribution, not accuracy. In the US it has 9 ratings with an average of 2.7. In Oct 15 a one-star review read: "Garbage AI slop… it's not accurate, and it immediately starts asking you to pay $43 subscription"; in August another said the forecast was "perfectly clear" but the water was "can't see a foot in front of you." The reviews from Southern Europe are the reverse, positive. Spanish: "Used it for a few months, very close to reality"; Italian: "Very helpful for timing and visibility in spearfishing." Whether it's accurate depends on where you are and what you compare it against.
Who it's competing with
The "will I see underwater today" niche was already crowded 2026 years ago:
| Product | Scale | How it differs |
|---|---|---|
| Windy.com / Windy.app / WillyWeather | Hundreds of thousands of ratings | General wave and tide data, no visibility estimate, no go/no-go verdict |
| Tide-station apps like Tides4Fishing | Ranks ahead in Portuguese and Spanish search | Also has visibility pages; it's the most direct rival in Southern European search |
| Spearo Vision / Go / Tracker(spearo.pro) | Single-digit iOS ratings | Same name, different company: machine-learning visibility plus diver reports, with 4 apps sharing a $4.99/month subscription; in October it also added breath-hold training, and the two are converging, so the names will eventually collide |
| DiveSight, Submarius | 31 US ratings, 12 in the store | Both launched in the first half of 2026, mainly English, one leaning toward scuba |
| Marla Blue, SpearFactor, Mogeo, Viz | Small | Each covers only one place: England, California, New Zealand or Sydney |
| SpearoVis, SeaThrough, spearo.uk, SpearoCY and others | Very small | Indie developers posting "I built a visibility tool" on Reddit and TikTok |
Big platforms don't do this, and small tools mostly cover one country in English only. Spearo is one of the few that combines a spearfishing-specific verdict, visibility, 85 countries and web pages in 9 languages.
If it were you
The bottom line: don't copy this one niche. It's already crowded, and Spearo has grabbed the small-language search spots first. The part worth copying is the template: a niche outdoor activity × public weather and ocean data × one page per city per language. Do it with a different activity, or with languages it hasn't covered yet.
Who it suits: indie developers who can build programmatic sites, know a bit of SEO, and can wire public data together (Open-Meteo, Copernicus, NOAA, national buoy and tide data). Ideally you play the sport yourself and know what players are actually agonizing over before they head out.
Who it doesn't suit: people who hope to win on model accuracy. Spearo itself hasn't won on accuracy, and weather-style forecasts draw a lot of complaints. It's also not for people planning to buy traffic to climb the charts: the chart bar for niche tools is low, but the overall pool is small, so ads rarely pay back.
How to build it: pick a sport where people "juggle three or four apps before going out": surfing, rock fishing, shore foraging, paddleboarding, kitesurfing, paragliding, wild swimming. Fold the factors they care about into one score and a red/yellow/green verdict, and add the searchable local information: regulations, entry points, closed zones. Keep the web version free and shareable; in the app, sell the full 7 days, multiple saved spots, and more alerts and pushes. Publish your data sources and error margins openly.
How to get users: launch the website before the app. Put one page on each coastal city and one regulations guide per country, and start with languages the big English sites neglect (Portuguese, Greek, Turkish, Croatian, Italian). Build plugins for big platforms like Windy, sharing only part of the data and linking the full version back to your own site. Find the one or two largest podcasts or forums in the activity's community and come up with something that makes people "gobsmacked" by the details, to earn a free shout-out.
Before when: get the pages built and indexed before summer 2027, ahead of the northern-hemisphere paddling season. Programmatic pages take months to go from indexed to ranking, so starting this winter is the right window. Wait until two or three rivals have shipped multilingual pages and the early movers are the ones who get the traffic.
How to tell you're reading it wrong: ① Six months in, Spearo's Android installs are still a few hundred a day and its iOS rating hasn't reached 500. That means multilingual pages like these bring in only a trickle of traffic, and the ceiling is too low. ② You've published several thousand pages, and three months later you still don't rank in the top 10 for core keywords in the target languages, or search engines are classing these template pages as low quality and not indexing them. That means the window for this approach has closed.
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Data and sources: App Store US and other store pages, version history and reviews (11-06); App Store Weather category charts across countries (10-28 to 11-06); Google Play store pages and install counts (10-29 to 11-06); AppBrain (08-15); spearo.app homepage, /science page and sitemap (11-06); Brave search results (11-06); Noob Spearo NSP:320 (08-24) and NSP:321 (09-02) episode pages; GitHub spearo-windy-plugin; spearo.pro; Reddit r/Spearfishing. Revenue is not public, paying users are an estimate; team makeup and location are unverified.
Research notes: competitor table, acquisition evidence, full research report
- Competitors
Name Where Launched Scale How it differs from this one Windy.com / Windy.app iOS 2015–2016 iOS about 290k / 180k ratings worldwide A general wind and wave platform with no visibility data and no go/no-go verdicts. Spearo built a plugin for it on Windy and rides its traffic. WillyWeather iOS 2013 About 370k ratings (mostly Australia) One screen for wind, waves and tides, popular with Australian spearfishers, but no visibility or verdicts Tides4Fishing / Tábua de Marés Web Early on Ranks ahead in Portuguese and Spanish search A big tide and fishing site with visibility pages, and Spearo's direct rival in southern European SEO. It doesn't do spearfishing-specific verdicts or regulations. Spearo Vision / Go / Tracker(VISIVO,spearo.pro) iOS 2026-04-05 Single-digit iOS ratings Same name, different company. Machine-learning visibility plus community reports, 4 apps share one $4.99/month subscription, watch-first. No multilingual web SEO. DiveSight iOS 2026-06-15 US 31 ratings Built for scuba divers. Visibility and fish forecasts for 28,000 dive sites, mostly English. Submarius iOS 2026-04-19 US 12 ratings Visibility for any coastal point, mainly US English, no multilingual coverage Marla Blue iOS About 2024 Small Visibility and diver reports for the UK and Ireland only SpearFactor Conditions Web 2025–2026 Small, but ranks #1 for "spearfishing forecast" Covers only 30 dive spots in California, backed by a podcast and courses Viz App / VIZ Sydney / Mogeo Other 2023–2026 Small Crowdsourced visibility, or limited to one region Surfline iOS 2010 About 47k ratings Serves surfers, not underwater - Where users come from
- Verified Multilingual programmatic SEO (web first): sitemap has about 5,800 URLs in 9 languages. In Brave, "previsão pesca submarina" (PT) ranks #1, Greek queries rank #1 and #2, "spearfishing forecast" ranks #2, Spanish ranks #4. The guide page 07-05 was indexed before the App launched on 07-10. Store buttons carry ct=organic.
- Verified Niche podcast Noob Spearo: the show notes for NSP:320 (2026-08-24) list Spearo.app; NSP:321 (09-02) 00:01:20 says "Free shout out to Spearo App, a completely free spearfishing forecasting app"
- Verified Windy.com plugin: GitHub drdrdrdr69/spearo-windy-plugin (2026-09-21, reads Official spearo.app plugin), searchable on windy.com/plugins; only 3 days, after 7 days it sends users back to spearo.app (utm_source=windy)
- Inferred Self-promotion in Reddit / Facebook groups: r/Spearfishing has many "I built a visibility tool" posts, but I found no post confirmed as coming from the spearo.app author.
- Inferred Paid acquisition: no records in the metaads library, no official TikTok account or creator videos. Play links carry the AppsFlyer af_sub1 parameter, so attribution is set up, and they may be preparing to spend.
- Verified In-product growth kit: widgets, morning summary push, a "turned green" alert, an invite-a-friend card added in October, and personalized offers plus payment-failure alerts added in November (App Store version history)
Spearo: Caça Submarina e Marés (spearo.app) research report
Data card: ios_6787949200 · App Store id6787949200 · developer account "Diana Dryn" · launched 2026-07-10 · research date 2026-11-06
Bottom line
A one-person studio in Poland (dryn.dev / Łukasz Dryński, sole proprietorship) built a "can I spearfish or freedive today" forecast. It converts waves, wind, tides, rain, water temperature and satellite water color into red/yellow/green verdicts and an estimated visibility in metres. It got traction mainly by building the website first, then the App: spearo.app has about 5,800 city and country landing pages in 9 languages, and ranks first or near the top for "underwater fishing forecast" searches in Portuguese, Greek and Spanish. Add two free mentions on Noob Spearo, Australia's biggest spearfishing podcast, and an official Windy.com plugin as two outside entry points. It is still small: 138 iOS ratings in total and about 38k Android installs. Apple's Weather category charts have a low bar, so chart positions make it look bigger than it is.
1. Basic data
| Metric | Value | Source |
|---|---|---|
| iOS global ratings count | 123 (10-28) → 138 (11-06), +12 over the last 7 days | appstore library app_day |
| iOS rating distribution | PT 19, FR 18, TR 16, BR 12, GR 11, ES 11, AU 10, IT 9, US 9 (average 2.7), NZ 8 | appstore library app_profile 2026-11-06 |
| iOS charts | Charted in the Weather category in 62–73 stores. Best Top Grossing ranks: Oman #8, Greece #9, Cyprus #9, Lebanon #11, Portugal #19, Brazil #23. Top Free: Egypt #7, New Zealand #8 | appstore library |
| Android installs | 34,945 (10-29) → 37,838 (11-06), +2,893 over 8 days (about 360 per day); listed on 2026-07-26; AppBrain records "5,000+" installs for 08-15 | googleplay library app_day; appbrain.com |
| Android rating count | 235 | googleplay library |
| Shipping cadence | iOS 1.3.24 (10-20) → 1.3.37 (11-05). Shipped 14 versions in two weeks. Recent additions: "Invite a friend", "subscription payment-failure alert + personalized offers", and a 3-day coastal view. | App Store version history |
| Pricing | Free to download, Pro / Ultra subscriptions. Annual Pro includes a 7-day trial. A one-star US review says "it asks for $43 subscription right away". | App Store description and reviews |
Read: Android volume is roughly 10× or more that of iOS (rough estimate from rating counts), so Android is the main market. iOS has only 138 ratings yet charts in 60 stores, because the Top Grossing bar in small-country Weather categories is very low. Greece, Cyprus and Oman reach the top 10 with only a few paying users. Portugal has the most ratings, and the App's pt-store name is the localized Portuguese "Caça Submarina e Marés". That fits the methodology page's "home coast" and "Cascais fit" lines, so the team's base is likely on the Portuguese coast, or at least the data started there (unverified).
2. Competitors
It does the same job: "can I see underwater today, and can I go in?" The niche has been crowded for 2026 years, and there's a name collision.
| Product | Where | Launched | Scale | How it differs from spearo.app |
|---|---|---|---|---|
| Windy.com / Windy.app / Windfinder / Windguru | iOS + Android + web | 2009–2016 | Windy.com has about 290k iOS ratings worldwide; Windy.app about 180k (appstore library) | A general wind and wave platform with no visibility data and no go/no-go verdicts. Spearo built a plugin for it on Windy and rides its traffic instead. |
| WillyWeather | iOS (mostly Australia) | 2013 | About 370k ratings | Australian spearfishers use it for wind, waves and tides on one screen (Reddit r/Spearfishing), but it has no visibility data |
| Tides4Fishing / Tábua de Marés | Web + app | Early on | Ranks above spearo in Portuguese and Spanish searches | Its website has a "visibilidade" visibility page, the most direct rival to spearo in southern European SEO |
| Surfline | iOS / web | 2010 | About 47k ratings | Serves surfers, not underwater |
| Spearo Vision / Spearo Go / Spearo Tracker(VISIVO,spearo.pro) | iOS + Android + watch | Vision 2026-04-05 | Single-digit iOS ratings | Same name, different company (the data card's recall merged the two, which is wrong). VISIVO's Vision also uses machine-learning visibility plus community reports, and 4 apps share one $4.99/month subscription. spearo.app is a single app, plus a worldwide web presence. |
| DiveSight | iOS | 2026-06-15 | US 31 ratings | Built for scuba divers. Visibility for 28,000 dive sites, 7-day forecasts, and fish prediction. Promoted on ScubaBoard. |
| Submarius(submarius.com/clarity) | iOS + web | 2026-04-19 | US 12 ratings | Horizontal visibility forecasts for any coastal point, mainly US English |
| Marla Blue | iOS + Android | Around 2024 | Small | Visibility and diver reports for the UK and Ireland only |
| Viz App (viz-app.com), VIZ Sydney (viz.net.au), Mogeo (New Zealand) | App / web | 2023– | Small | Crowdsourced visibility, or limited to one region |
| SpearFactor Conditions | Web | 2025–26 | Small | Only 30 places in California, free, with a podcast behind it |
| spearo.uk, SeaThrough, SpearoVis, VisPro Dive, SpearoCY | Web / App / TikTok | 2025–26 | Very small | Independent developers each covering one slice (UK, Cyprus, Spanish-speaking markets…), typical of the "I built a visibility tool" Reddit / TikTok posts |
| DiveViz | App | Relatively early | Small | US scuba visibility reports |
Bottom line: there are many competitors, but nearly all are small tools for one country or one diving style, or large platforms that ignore visibility. spearo.app is one of the few that combines spearfishing-specific use, visibility, 85 countries, 9 languages, and both web and App.
3. Where users came from (growth tactics)
3.1 Multilingual programmatic SEO (confirmed, main channel)
- The spearo.app sitemap splits into 9 languages, about 5,800 URLs in total: en 3,387, es 517, fr 425, pt 359, it 244, el 229, ru 209, hr 207, tr 201 (2026-11-06 from the live sitemap). Each coastal city gets a forecast page, and each country gets a regulations plus seasonal guide (for example "Ψαροντούφεκο στην Ελλάδα" and "Pesca submarina en España: licencia por comunidad…").
- Brave search check (2026-11-06):
- "previsão pesca submarina" (PT) → spearo.app/pt ranks #1, and #2 is its city page too;
- "πρόγνωση ψαροντούφεκο ορατότητα" (GR) → #1 and #2 are both spearo.app;
- "spearfishing forecast" → #2, just behind SpearFactor;
- "previsión pesca submarina visibilidad" (ES) → #4.
- The website came before the app: guide page 2026-07-05/06 was indexed first, and the App 07-10 launched later. The App description's first line reads "Spearo (spearo.app)", and the store buttons carry
ct=organicandutm_source=organic. robots.txt explicitly allows GPTBot and OAI-SearchBot, so it is also positioning for AI search results. - This explains why the ratings cluster in Portugal, France, Turkey, Brazil, Greece and Spain: these are small-language underwater fishing markets that the big English platforms don't cover.
3.2 Free recommendations from the niche podcast scene (confirmed)
- Noob Spearo (Australia, one of the largest underwater fishing podcasts in the world) NSP: 320 (2026-08-24) episode notes list "Spearo.app — Free spearfishing-specific forecasting tool"; NSP: 321 (2026-09-02) at 00:01:20: "Free shout out to Spearo App, a completely free spearfishing forecasting app, and the level of detail that gobsmacked Shrek". The host calls it a "free shout out", not paid sponsorship. The noobspearo.com podcast index page also links to it.
- The data matches: Australia has 10 rated entries and New Zealand 8, and New Zealand's free category chart is #8.
3.3 Windy.com plugin (confirmed to exist, effect unknown)
- GitHub drdrdrdr69/spearo-windy-plugin (2026-09-21 created, labeled "Official spearo.app plugin", 0 stars), and it is searchable in the windy.com/plugins listing as "Water visibility forecast … Data by spearo.app". The plugin only shows 3 days; the full 7-day forecast requires jumping back to spearo.app via a link tagged
utm_source=windy, a funnel that pulls Windy's huge user base back to its own site. - The docs include a Russian version. The App supports Russian and has ratings from the Ukraine store, so the team may speak Russian (not verified).
3.4 Paid acquisition (no evidence found)
- The metaads library (since 2026-11-01) has no spearo-related advertisers; x-radar returns 0 results for "spearo" over the past 120 days; there is no official spearo.app account on TikTok and no creator videos.
- However, the Play Store link carries AppsFlyer-style
af_sub1parameters, showing it uses an attribution tool and may buy ads later. Right now there's no sign it is spending.
3.5 In-product retention and monetization
- Home and lock screen widgets, a daily morning summary push, "remind me when it turns green", an "invite friends" card (added in October), and failed-payment and personalized offer reminders (added in November). A classic subscription-app growth kit.
4. Why it charted
- The pain point is real and has gone unsolved: on Reddit r/Spearfishing, people have repeatedly asked for an app that forecasts visibility, and the answer has always been "none exists, check WillyWeather / Windguru yourself". spearo's copy speaks to exactly this: "Most of us check three or four apps before a dive … then find murky water anyway".
- Web-first plus 9 languages of programmatic SEO captures small-language search traffic: it ranks first in Portuguese and Greek, earning organic traffic in markets others neglect. The countries with the most iOS ratings are exactly the countries speaking those languages.
- Makes the tech credible: the /science page covers Sentinel-2 satellite depth mapping, Copernicus water color (ZSD), buoy mirrors in 9 countries, and validation results with an MAE of 2.25 m, and it explicitly says "where it doesn't work, we mark no coverage". This kind of transparency earns trust in the niche; the Noob Spearo host's reaction was "gobsmacked" by the detail.
- Free web for acquisition, subscriptions in the App: the niche calls it "completely free", while inside the App the 7-day forecast, multiple saved spots, and multiple alerts sit behind Pro.
- Iterates extremely fast: 14 releases in two weeks. It expanded from 26 countries and 1,100 cities in July to 60+ / 85 countries and 2,600+ cities now, and coverage keeps growing.
5. Differentiation
- Compared with the big platforms (Windy, Windfinder, Surfline, WillyWeather), it answers only one question, can I see anything when I get in the water, giving a 0–10 score with red, yellow or green, plus visibility in meters, closed fishing zones, minimum catch sizes, and night fishing legality. These needs are specific to underwater fishing.
- Compared with similar niche tools (Marla Blue, Mogeo, SpearFactor, Submarius, Spearo Vision, SeaThrough), its edge is coverage and language. Rivals usually cover one country and English only; it covers 85 countries and 9 languages, and every city has a searchable page.
- The main reason it's winning is distribution: coverage × language × web SEO, not a better model. The US store has 9 ratings averaging 2.7, and the top negative review says "AI slop, inaccurate, and $43 upfront", so the accuracy of the model hasn't been shown to beat competitors. The reviews from southern Europe (in Spanish and Italian) are positive: "used it for a few months, very close to actual conditions".
6. How many people know about it
- No media coverage, no founder posting revenue, nothing on TrustMRR or X (x-radar: 0 results). Third-party app intelligence sites (AppTail, StoreIntel, AppTrendKit, MWM) only auto-index it.
- Only a bit of spread within the underwater fishing community (two Noob Spearo episodes). Verdict: it's spreading in a small circle.
7. Copycats
- Strictly speaking, nobody has copied it yet. But around the same time a batch of indie developers built underwater fishing visibility forecasts: SpearoVis (Spanish TikTok), VisPro Dive, SpearoCY, SeaThrough, spearo.uk, DiveSight, Submarius.
- VISIVO (spearo.pro) has the same name, and 2026-10-29 added a "Spearo Breath-hold Trainer"; spearo.app's Android version also added breath-hold training. The two are converging in features, and the name clash could turn into a trademark dispute.
8. What to borrow
- "Vertical outdoor sport × public data × small-language landing pages": convert public weather, ocean and satellite data (Open-Meteo, Copernicus, NOAA, national buoys) into a verdict for a niche sport, with an SEO page per city and per language, taking first place in languages the big English sites ignore. The same template could move to surfing, shore fishing, foraging, paddleboarding, kitesurfing, paragliding.
- Piggyback plugins on big platforms: build a plugin for a mass-market tool like Windy that shows partial data and sends users to your site for the full picture.
- Publish the methodology: document data sources, error margins and uncovered regions to earn niche trust and podcast recommendations.
- Free web, paid app: the web gets found and shared; push notifications, widgets and multiple saved spots in the app are what collect money.
9. Still unclear
- Real revenue: the top-grossing rank comes from the small-country Weather category, which has a low bar; paying users may be only dozens to hundreds (unverified).
- Who's behind it: the Apple developer account is Diana Dryn; the website and legal entity is dryn.dev (Dryn Łukasz Dryński, a sole proprietorship (JDG) in Warsaw, Poland), who also built the Polish events calendar dziś.app and an Ethereum learning site. The Diana Dryn found online is a Ukrainian model and most likely unrelated. The data "home coast" is Portugal; how many people are on the team and where they are has not been verified.
- Of the roughly 360 daily Android installs, how many come from search, the store, or Windy is unknown.
- Whether Windy officially featured the plugin in its recommendations and how much traffic it brought is unknown.
- Whether it buys Google Ads / Apple Search Ads: our libraries don't cover this.
Sources
- App Store: apps.apple.com/us/app/spearo-spearfishing-forecast/id6787949… (description, version history, US-store negative reviews)
- Google Play:play.google.com/store/apps/details?id=app.spearo
- Website: spearo.app/en, spearo.app/en/science, spearo.app/sitemap.xml
- Developer entity: dryn.dev/
- Noob Spearo: www.noobspearo.com/nsp320-decoding-the-wild-with-johnny-mitc…, www.noobspearo.com/mbp/ (NSP: 321)
- Windy plugin: github.com/drdrdrdr69/spearo-windy-plugin
- Same-name rival: spearo.pro/apps (VISIVO)
- Competitors: submarius.com/clarity, marla.blue, viz-app.com, conditions.spearfactor.com, the DiveSight thread on scubaboard, several Reddit r/Spearfishing threads (ibt72z, 1qpn6hm, 1x42ry1, 1t5jqme)
- Internal libraries: appstore (app_profile / app_day, 2026-10-28 to 11-06), googleplay (app_profile / app_day, 2026-10-29 to 11-06), metaads (no records), x-radar (0 results)