HabitKit: A GitHub-Style Grid Built a $602,000 Year — With $112,000 of It Landing in January Alone

A habit app that fills small squares for every day you keep the streak — anyone who has seen GitHub’s contribution graph can picture the grid immediately. HabitKit, released in November 2022 by German indie developer Sebastian Röhl, stands on that single idea.

In his 2025 year-in-review, Röhl writes that he “made over $600k in total revenue with HabitKit.” The breakdown is published too: $602,000 for the year, $28,000 MRR, 25,100 paying subscribers. Downloads run 272,000 on the App Store (4.8★ from 6,630 ratings) and 290,000 on Google Play (4.6★ from 9,443 ratings).

But the total is not the interesting part of this case. January alone brought in $112,000, roughly 19% of annual revenue arriving in one twelfth of the year. The business rides a single calendar spike: New Year’s resolutions. Every figure below comes from Röhl’s own Substack review and his Indie Hackers post.

How the numbers moved

The April 2023 return to employment is easy to skip past. Five months after HabitKit shipped, indie work still did not cover his living. That interruption is why he describes 2025 as his first year with twelve consecutive months full-time.

Why one grid worked inside the store

Röhl describes what he set out to build: “a habit tracker that could display my consistency in a grid format, similar to GitHub’s contribution graph.”

The real leverage of that idea sits not in the feature but in the store screenshot. Habit trackers are a category where features barely differentiate; reminders, checklists and stats exist in every app. Introduce a visual element legible at a glance, and the app separates from its neighbors at the thumbnail stage of a search result. Better still, the grid previews what the user’s own record will look like once filled, so the screenshot is a preview of the post-use state.

The numbers confirm this was the main path. Per Röhl, “~98% of my new users find my apps directly on the App Store or Google Play.” Acquisition is essentially all in-store search, which makes ASO, keyword research aimed at ranking in multiple countries, the spine of the business. Breaking into the top 5 for “habit tracker” in the US App Store in 2025 is described as the turning point after which monthly revenue stabilized above $40,000.

The architecture is light too. The app is built in Flutter, data is stored on the device, and no backend is required. With no server bills and no custody of personal data, one person can run a 560,000-download install base. Compared with the case that rebuilt five Flutter apps to reach ¥100k a month, the same technical stack yields results an order of magnitude apart, the difference being the choice to concentrate on one app and win store search.

A business where 19% of the year arrives in January

$112,000 of $602,000 in January. That skew follows directly from a category tethered to an annual ritual. Röhl attributes it to a combination of “the traditional New Year’s resolution hype for habit tracking apps” and HabitKit being featured in a YouTube video.

Seasonality itself is unremarkable. In an indie context the implications are heavier: if one month decides a fifth of the year, losing rank in January sinks the whole year. ASO has to be funded year-round precisely because the ranking must already be in place by late December. Cash flow, in turn, front-loads severely. $602,000 a year looks like $50,000 a month, but the actual shape is $112,000 in January and the $40,000s thereafter.

A note on the figure in this article’s frontmatter: we recorded the published MRR of $28,000 as monthly revenue. Actual monthly revenue including lifetime license sales is higher, but we avoid mixing an annual-total-divided-by-twelve estimate into the site’s aggregates.

What did not work — and whose land this is

Röhl tried Instagram marketing for a couple of months and dropped it when his motivation ran out. Given that 98% of acquisition comes through store search, that reads both as a channel that did not fit him and as evidence that when one channel dominates, the marginal utility of the others is low. His recurring line (“Sometimes, doing less can actually lead to more success”) is best read in that context.

Some risks cannot be reduced, though. In August 2025, Apple temporarily pulled HabitKit from the App Store over an address-verification failure (restored within 24 hours). Google Play separately threatened removal because the app linked to his Substack newsletter, and he stripped external links from the Android build. The lesson he draws from 2025 sits on top of those two incidents: “Platform risk is real. Never forget that you’re building on someone else’s land.”

In a business that leans 98% on the stores for acquisition and 19% on January for revenue, those two risks multiply. Disappear from the store in January and a substantial share of the year disappears with it.

FocusKit, the second app, made $52 MRR in its first month

The grid is an idea that lands hard on people who know GitHub. The same invention is not lying around in every category, and the clearest evidence comes from Röhl himself. FocusKit’s first month (1,600 downloads, $874, $52 MRR) sits more than two orders of magnitude below HabitKit. A second app from the same developer using the same playbook does not automatically climb, and his own numbers say so.

On the nature of the figures: all amounts here are self-disclosed and unverified by any third party. They are revenue, not profit. Take-home after store commissions, taxes and tooling is not published. Churn is not disclosed either, so how stable a base that $28,000 MRR represents cannot be judged from outside.

Our read

What makes HabitKit worth recording is less the amount than the granularity of what one developer publishes. Few cases include the monthly skew alongside the annual total, download and rating counts, the failed predecessor, the stretch spent back in employment, and the removal notices from platforms.

Set next to a single-purpose app like TalkNotes or the anniversary app that stacked MRR through subscriptions, a pattern repeats: in solo mobile development, the center of gravity sits less on what you build than on how it appears in store search results. HabitKit put that entire center of gravity onto one visual element.