Py - Learn to code on the go 📱
hackattic - No nonsense, real world programming challenges
Mimo - Learn how to code on your iPhone📱
Code Fight Club - A fight club you can talk about. Less punching, more coding.
Enlight - Performance and Error Monitoring. We keep an eye on your applications and notify you about performance issues and errors.
Codewars - Achieve code mastery through challenge.