The same fishing tutorial in 13 languages: how an Amsterdam solo developer got a fishing journal app into the charts in 8 European countries

VISDEX is a fishing journal app built by a Dutch developer. It launched in July and had almost no users outside the Netherlands before October. Starting Oct 9, it opened 13 TikTok accounts by country and posted the same fishing tips videos translated into each country's language, generating several million organic views in a month. By Oct 28, the app had followed with 15 languages. Over the next 8 days, Google Play installs grew from 4,763 to 12,364, and it appeared on the sports charts in Poland, Germany, Sweden, and Hungary. The product itself is an old category; what's worth studying is this "one script, N countries" approach.

A video on method feeder hit 278k views in Poland

In Nov 1, the TikTok account @visdex.pl posted a video: "Method feeder: the rod tip bends, and the fish has already hooked itself. This is how to catch bream, roach, and carp." No face on camera, just voiceover, covering how long the short hooklength should be and how to rig the bait, ending with a line pointing to the app. By Nov 6, it had 278k views and 4,191 likes.

Three days later, the same video appeared on @visdex.hu in Hungarian, nearly word for word, with 89.6k views. There were also versions on the Dutch, UK, and Italian accounts. Looking through these accounts' videos, titles like "big perch don't hang out with small perch," "drag set to a quarter to a third of the line strength," and "same water, one angler catches three zander while another gets skunked; the difference is what you know before you leave" were each posted in every language. The style is consistent and frequent, which looks like batch production with AI (inference).

The Hungarian account only posted its first video in Oct 29. A week later, VISDEX ranked #3 on the Hungary iOS free Sports chart, when it had only 1 ratings in Hungary (App Store Hungary, 11-06).

What it is

A fishing journal, but built like a collection. Each catch you log (species, length, weight, bait, photo, and spot) lights up in your collection; the Dutch version has 88 species, with automatic bronze, silver, gold, and legendary tiers based on length. Species you haven't caught yet stay empty, waiting for you to fill them.

Around the collection, it adds: national, provincial, and city leaderboards (counting only officially measured catches), angler competitions for friends (most fish, biggest, most species), a daily "bite score" based on wind, pressure, temperature, and moon phase, and per-species minimum sizes, closed seasons, and whether the fish can be kept. The website tagline is "Catch. Collect. Beat your records."

Logging, collection, leaderboards and community are free. Pro unlocks AI fish ID from photos (it also estimates length during a session), a bite forecast for the next week, bait suggestions and full stats. The Dutch store page lists €6.99/month and €29.99/year, with two more tiers at €2.99/month and €19.99/year (App Store Netherlands, 11-06; from outside it isn't clear whether the two price sets are a test). When Pro launched, new users got 3 months free.

The developer is Niels Zwetsloot, based in Amsterdam, and this is his only app.

Numbers: volume is on Android, iOS looks small

Sources: Google Play and App Store country charts and store pages, 10-28 to 11-06.

iOS has only 82 ratings, yet Play has passed 12k installs: European anglers use Android more. The two iOS grossing ranks suggest some people are paying for subscriptions, but the bar for a small-country sports grossing chart is low, so the money can't be large (inference).

Cold start was done locally in the Netherlands. The July 22 Instagram launch post said "427 anglers have logged 1,864 catches and 35 species"; by Nov 2, a Hungarian-account video said "VISDEX already has over 20,000 catches."

Where the users come from

TikTok, one account per country. Accounts visible to 11-06:

The 59 visible Dutch-account videos total 1.85M views, the UK account 39 videos 960k, the Italian account 31 videos 870k. The order accounts were opened matches when each country's chart entries appeared: the Netherlands first, Play Netherlands #4; the Polish account posted a 278k video, Play Poland #7; the Hungarian account came last, iOS Hungary #3. TikTok's European ad library shows nothing for it, so this is all organic traffic.

Most videos only teach technique and don't mention the app. A few do talk about the product, and the pitch is content-style: "A pike caught in Friesland turned into tips for anglers at Masurian lakes a week later, that's how VISDEX works"; "Fish are biting and you're still choosing a species and measuring length? Start a fishing session, snap a photo, and get back to fishing."

Where the localization lands. The Oct 28 1.0.18 update said "VISDEX now supports 15 languages," and store titles were switched to local language too: German reads "Fangbuch & Angeln," Dutch reads "Visdagboek & Vangsten." People who search the brand name from a video land on a page in their own language.

Small-country category charts. In Hungary, Czechia, Romania and similar countries, a few dozen downloads can put an app in the iOS Sports Top Free top 30. Once TikTok pushes it onto a chart, the chart itself adds another layer of exposure.

What's missing. No press coverage found, no discussion on X or Reddit, nothing on Dutch fishing forums. Whether it runs Meta ads is unverified.

Who it's competing with

Sources: App Store country stores, Google Play, Fishbrain careers page, 11-06.

A fishing journal isn't a new idea, Fishbrain has been doing it for over a decade. VISDEX doesn't win on features. It takes the part Fishbrain hasn't covered: smaller European language markets, a local species guide and regulations for each country, and leaderboards at the province or city level. It also doesn't compete with the official Dutch app: the official one handles licenses and rules, VISDEX handles fun. Several similar personal projects appeared around the same time and none gained traction; the difference is the TikTok account setup.

What it hasn't proven yet

• Money. Subscriptions are new and pricing is still being tested. Grossing ranks show up only on small charts like Austria and Germany, and monthly revenue isn't visible from outside.
• Retention. Fishing is seasonal, and fewer people go to the water in European winters. Whether the cohort that joined from October still uses it next spring can't be seen yet.
• How long the content accounts can last. 13 accounts running the same scripts and batch AI-style content. Whether TikTok downranks it is the biggest risk to this approach (inference).

If it were you

B. The approach is clear, cheap, and almost unnoticed, so it's worth trying. But the money-making ability of a fishing journal itself hasn't been proven, and it already covers 15 languages in Europe, so copying its category and region isn't useful. What's worth taking is the approach, applied somewhere else.

Who it suits: individuals or small teams of two or three who know an outdoor hobby well (fishing, birdwatching, mushroom foraging, hunting, metal detecting, diving); people who can batch-produce scripts, voiceovers and image-text videos with AI; people who can build multilingual apps. Ideally you're into the hobby yourself and know which trivia gets views.

Who it doesn't suit: anyone wanting to build another fishing journal in Europe (VISDEX is already there, and so is Fishbrain); anyone aiming at the US English market (Fishbrain and Fish AI are far ahead in scale); people who only want to build product and don't want to post content every day.

How to do it: pick one of two routes. One is to do fishing in a new region: Japan, South Korea, Brazil, Mexico, Southeast Asia, places with large fishing populations, weak local coverage from Fishbrain, and where VISDEX hasn't gone yet. Build a local species guide, regulations, and province/city rankings for each country. The other is to copy the structure for a different hobby: "local species guide + bronze/silver/gold grades + regional leaderboards + competing with friends + local rules", logging free, with Pro selling AI recognition and forecasts at a €20–30 annual tier.

How to get users: do what it does. In one country, post technique-focused short videos in the local language, no face, no hard ads, ten or so a week, and see which topics get views. Then translate the scripts that work into other languages, open a separate account for each country, and make the app title and store page local too. Start with small countries and aim for the category charts, since the bar is low and charting brings free exposure.

When to start: if you're doing fishing, the spring season in the Northern Hemisphere starts around 2027 (3–April), so have the guide, rankings and content accounts ready before then, and use winter to build up content. Doing South America or Southeast Asia isn't tied to this season, so the sooner the better, since once the approach gets noticed, similar accounts will multiply.

Signs you've read it wrong: (1) if in spring 2027 VISDEX's Play install growth doesn't recover to where it is now, and its iOS grossing ranks disappear, that means these users installed but neither paid nor stayed; (2) if your account has been posting for a month and no single video ever tops 10,000 views, the hobby has no audience on TikTok in that country; (3) if TikTok starts mass-throttling faceless AI image-text videos like these, VISDEX's country accounts will all see views drop together.