0 ratings, #10 in Argentina's Food & Drink chart: Moonvine, the "is today a good day to open wine" App, hasn't really taken off yet

Moonvine is an app that calculates "fruit, flower, leaf and root days" using biodynamic methods, telling you which days are good for opening wine and which for sowing. It launched on Oct 30, and a week later hit #10 in Argentina's App Store Food & Drink Top Grossing chart, yet has zero ratings globally. It looks like a "nobody knows it but people are paying" promising start. Looking closer, the bar for this chart is low. What's really worth studying isn't the ranking but the approach one former Instagram engineering lead used to build it alone.

Nov 6, today is a root day

On Nov 6, open moonvine.app and the first line on the homepage reads: "Right now: Root Day, poor for wine". It's a root day now, not good for drinking wine; the next window starts Saturday at 9:00 (UTC). Below are two buttons, one for the App Store and one for Google Play, and below that a small line: "Or check today on the web".

The same day, the app first appeared on a chart: #10 in Argentina's Food & Drink Top Grossing, #132 in the UK, #152 in the US (App Store, 11-06). All three countries show 0 ratings, and it didn't make any country's overall chart. In Argentina its Spanish name is "Moonvine: Calendario de vino".

What it is

Biodynamic agriculture is a farming tradition dating back to 1920. German Maria Thun turned it into a sowing calendar: depending on which zodiac sign the moon is in, that day counts as a fruit, flower, leaf or root day. Some people in wine circles believe that opening wine on fruit or flower days makes it smell better, and that root days make it taste stuffy.

Moonvine turns this calendar into two modes:

• Wine tasting: fruit and flower days are marked as "good for opening wine" windows, down to the exact start and end times;
• Gardening: sowing windows for four crop types (fruit, flower, leaf, root), and when the moon hits nodes, perigee, or eclipses, the traditional "pause" periods, it warns you not to plant.

Free to view today and past dates, save favorite times, and join community votes (after drinking, report whether a bottle was "tasty" or "stuffy"; results show once a window collects 10 votes). Paid unlocks future dates, upcoming windows, home and lock screen widgets, day-change reminders and Siri. Annual subscription or lifetime one-time purchase; prices are only visible in the app, about $6.99/year and $17.99 lifetime (unverified).

It runs on iPhone, Android, and a free web version. The app supports 6 languages (English, French, Spanish, German, Portuguese, Italian), and the website adds Polish. The calendar is computed locally on your phone, with no account and no email required. The website also has an article explaining that in 2017, a New Zealand blind tasting had 19 professional tasters drink 12 Pinot Noirs, and found no difference between fruit days and root days. Its takeaway: "This is a ritual, it costs nothing, and your tongue decides."

One thing it doesn't explain: the website FAQ says the iPhone version isn't available in France.

Who makes it

Developer Colin Hanson, per his personal site: 15 years of software work, including leading the AI voice translation team for Reels at Instagram, a feature Meta named in its Q4 2025 earnings call. Before that, he rose to engineering director at Zocdoc.

Now he builds apps solo. Moonvine is the third: earlier there was Veil, a white noise app (he says it had a few thousand monthly users), and Wordchute, a daily word puzzle game (he says over 1,000 people played in its first week). The last line of his personal site reads: "Looking for full-time engineering roles and good contract projects." Shipping one app a month, available on three platforms in 6 languages, with 3 releases a week (the latest, 1.0.3, came out Nov 5), is no longer hard for someone with big-company experience who uses AI to write code. Half of these apps are products, and half are portfolio pieces.

What the #10 ranking is worth

Not much. The same day, the older rival When Wine Tastes Best (published by UK house Floris Books, with 31 ratings in the US and 10 in the UK, after 13 years on the market) sat on Food & Drink charts in 54 countries: #40 in Taiwan, #48 in Finland, #75 in Argentina. In many of those countries it had zero ratings (App Store, 11-06).

The Food & Drink category has few paid apps to begin with, so a few in-app purchases can push a small country's chart. Argentina is a wine country, and Moonvine happens to have a Spanish version, so a handful of purchases there is the most likely explanation (inference). As of Nov 6, it has appeared on the chart only that one day.

Where users come from

The visible channels are just these:

• Search traffic from its own website. moonvine.app's sitemap has 308 pages: 2026, with one calendar page for each month of 2027 years, multiplied by 7 languages. Plus long-tail articles like "What is a fruit day", "Are biodynamic calendars accurate" and "Why different calendars don't match". The earliest went up Oct 4, nearly a month before the app. The live "Right now: Root Day" on the homepage is the hook, and store links carry source parameters so it can track how many people the website sends over.
• Store search. Titles are written separately for each language: Spanish Calendario de vino, German Weinkalender, French Calendrier du vin.
• The author's own social accounts. An Instagram Reel: "I made a little app for people who love wine 🌙🍷", with unknown views and engagement.

Beyond that, nothing: it doesn't show up on TikTok, nobody mentions it on X, and there's nothing on Reddit, Product Hunt or in the media. There's no sign of paid ads.

Who it's competing with

Where Moonvine beats the rivals is real: subscription or one-time purchase instead of rebuying every year; widgets and reminders turn "checking the day" into a glance; the gardening mode widens the audience beyond wine drinkers to a larger moon-gardening crowd; and its multilingual website is more extensive than anyone else's. But it uses its own algorithm, not Thun's official data, so its dates can differ from the paper almanac, and its website has a dedicated article explaining why.

What matters more: this autumn, several people suddenly started building "is today a fruit day" web pages. This idea isn't unique to Moonvine, and search results are already crowded.

If it were you

C: you can learn an approach here, but this one topic isn't worth it. Moonvine hasn't proven that anyone pays, and its chart entry comes from the low bar of a niche category. Biodynamic wine tasting is a very small circle, and same-theme web tools have piled up this autumn.

Who it suits: indie developers who can code and have a niche hobby community they know well (fishing, hunting, gardening, succulents, haircut timing...), who want to build a small "local algorithm + search traffic + widget subscription" product in a month as a portfolio piece or side income.

Who it doesn't suit: anyone hoping to make a living from it; anyone who copies a wine-tasting calendar to compete with Moonvine and the older rival. The audience is small, search traffic is already split among several web pages, and the official Thun dates come with a licensing barrier.

How to do it: copy the structure, change the audience.

1. Find a hobby with a "timing" tradition where people will pay for reminders: moon fishing tables, hunting time schedules, moon gardening, or Chinese almanac day selection.
2. Write a local calculation engine (astronomy formulas plus an open-source astronomy library, so moon positions compute instantly), with no server.
3. Launch a free web version first, batch-generating calendar pages and long-tail Q&A pages by year × month × language to capture search traffic; put a live "what day is it today" on the homepage.
4. Free in the app for today, paid for future dates, widgets and day-change reminders, with both subscription and one-time purchase options.
5. Like Moonvine, state plainly that there is no scientific evidence; that honesty actually reassures people.

How to get users: search is the main channel, with the website going live a month before the app; write store titles separately for each language; add hobbyist communities and your own social accounts. Niche categories' Top Grossing charts are easy to reach, and once you're on one, you can screenshot it as social proof.

When to start: the wine-tasting topic is already late, and same-type web pages that appeared this autumn will fill search results by the first half of next year. Other hobbies have no time limit, but gardening tools are best launched before the 2027 spring sowing season (2–March).

What would mean we misread it: If Moonvine's ratings climb into the dozens or hundreds in the US or UK by December, and it stays in the top 50 of the Food & Drink charts across several countries for days on end, or the author publishes revenue, that means the wine-timing crowd will pay more than we assumed, and this idea deserves a closer look as a B. If it drops off the charts instead, and the author stops updating after starting a new job, then it was just a nice portfolio project, nothing more.