Live
Pi-Squared
A daily maths puzzle on iPhone. Built in five weeks, ranked thirteenth in its category on launch day, and 20,052 installs later it is still the best teacher I have had.
What it is
One maths puzzle a day, the Wordle shape applied to numbers. It started life as a maths-learning app and became a game, which turned out to be the single most important decision in the whole project.
The numbers
Eighteen months of Firebase analytics gave me a uncomfortable picture. 48.9% of people chose guest over signing up. 82% of active users were in one country. Week-on-week retention held at 78%.
Launch day put it thirteenth in its category, and it never scaled past that. I wrote the thing up honestly instead of picking the flattering cuts.
What it taught me
I pivoted it from learning to gaming on a gut call, and the gut call was right -- people will play something daily that they will not study daily. I rebuilt the first screen three times in six months, which tells you how badly I got it wrong initially and how long I took to admit it.
It is the reason Braindex took seventeen days instead of five weeks.