Product study: ThinkCool

  • Post by William Saar
  • May 16, 2022

ThinkCool is a mobile app to help make better decisions by following a structured process inspired by the book Thinking, Fast and Slow.

The app was supposed to be called ThinkSlow but I discovered that name was not available when uploading the app to the iOS app store, even though there was no published app with the name. I quickly had to find a name where the domain and app store names were available and modified the logo that the designer had created, unfortunately resulting in a name with more associations to air conditioners than the behavioral psychology book.


✅ Site published at and the app is still available in the Android app store, but delisted in the iOS app store.


❌ Acquire customers through ads, and sell the app at a profit
❌ Overcome the barrier of a paid app with a free period that generates reviews
✅ Learn React Native
✅ Publish an app in both iOS and Android app stores
✅ Learn Facebook ads

Main learnings

Reserve new app names in the Apple app store before starting development. Searching for published apps with the name is not enough to know a name is available.

Apps need aggressive encouragement to get reviews.

Market outcomes

ThinkCool was released in 2019 and got featured on ProductHunt. The app was free for the first two weeks to get reviews in the app stores. It did get a number of installs but no reviews. From interviews with other app builders, it seems those annoying in-app popups that request reviews could have made big difference for this.

After the initial weeks the app turned into a paid app costing around $3 per install and I spent a couple of hundred dollars on Facebook ads, getting many impressions but leading to few paid installs. Over the following year the app got the occasional monthly customer that seemed to find the app organically through the iOS app store (but really too few to tell) and made a total of $30 before the Apple developer license expired and the app was delisted on iOS. The app did not get any paid installs on Android.


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