Mobile app idea: what to check before you pay a developer

A mobile app is expensive to build: two platforms, store reviews, updates that never stop. Before you commit that budget, three questions can be answered from a browser: which apps already own the space, whether they're free, and who would pay for yours.

The app stores are the first and most honest source

Search for your idea in the App Store and Google Play with several phrasings. For each app you find, note the number of ratings, the average, and the date of the last update. An app with three ratings last updated two years ago barely counts; one with thousands of ratings updated this month is a real competitor.

For a roommate app that splits bills and chores, the search found Splitwise ranked #78 in Finance on the US App Store with 28K ratings at 4.0, and chore apps rated highly on their own: Flatastic at 4.7 from 287 ratings, Nipto at 4.7 from 878. Each half of the idea was already covered. The only angle the sources supported was bundling the two.

Free sets the reference price

In consumer apps the question isn't “how much should I charge” but “will anyone pay”. In the roommate report, Splitwise's Pro tier came out around $4.99 a month or $39.99 a year for US users, and two sources disagreed on the exact price. Nipto was reported by an App Store reviewer at 1.99 a month. Reddit users said $1 to $3 a month felt reasonable. The report's suggestion followed: keep the core free and sell a household plan around $2.99 a month.

When a market runs on free, three routes exist: ads (which need a lot of users), a paid feature the free apps lack, or a different buyer with a budget. Choose before you build, because each one leads to a different app.

Look for frustration, not praise

The one- and two-star reviews of competing apps are the best feature list you'll get. So are “alternative to” threads. In the roommate example, people went looking for Splitwise alternatives after its free tier was limited to a few expenses per day, and a 2025 r/roommates thread was titled “It's 2025 and there still isn't a good roommate app”. That is a real opening. It still has to be large enough to fill a store listing.

The test that settles it

The report suggested a one-page site describing the combined app with its free core, posted for feedback in r/roommates and r/roastmystartup, where roommate apps already get discussed, plus replies in live threads asking for Splitwise alternatives. Visitors join a waitlist and answer one question about paying. That's a week of work, against months for an app on two platforms. If the test fails, the app would have failed too, only more expensively.