Timebug - Productivity & life management app to guide self discovery
stretchly - break time reminder app
Habit Challenge - Habit Challenge is an elegant mobile app that helps you to create new daily routines and keep you on track.
Workrave - Workrave is a program that assists in the recovery and prevention of Repetitive Strain Injury (RSI).
Youtine - Develop self-discipline, without using an app.
BreakTimer - Save yourself from RSI and eye-strain BreakTimer allows you to set up customizable breaks and will remind you to take them. BreakTimer is free and open source and available for Windows, macOS and Linux.