iOS apps

Super Simple Draw

Minimalist drawing app

Try on web: https://draw.lei.fyi

More features on App Store

Just Keep Favorite Photos

Easy photo management

Cipher Challenge

A cipher decoding game

cipher challenge

Try on web: https://cipher.lei.fyi

More features on App Store

simple web apps

Cipher Challenge

A simple cipher decryption game. On iOS and Mac OS, it’s strongly recommended to download the app instead, so that you can track the solved puzzle and avoid duplicates.

Confidence interval

Linear regression

Clock

Time conversion

Text to speech

Can you read this?

Cryptarythm