I m building Numday, a daily mental math challenge for Android.
The core idea is simple: everyone gets the same chain of 7 calculations each day, has 90 seconds to solve it, and then compares scores in global rankings or private leagues with friends.
We made one product decision early: you can play first without creating an account. Sign-up only appears after you see your score and want to publish it or enter the leaderboard.
Numday is a 90-second daily mental math challenge for Android. Everyone gets the same 7-calculation chain each day, so scores are easy to compare. Play solo, climb the global ranking, or create private leagues to compete with friends, family, classmates, or coworkers. You can try the challenge without an account; sign in only for rankings and leagues.
