Habitica - Habitica is a free habit building and productivity application.
Habit List - Create good habits and break bad ones with the app that keeps you focused.
Loop Habit Tracker - Loop Habit Tracker (AKA uhabits) helps to create and maintain good habits in order to achieve their...
Momentum - Agile goal and performance management
Purp - A smart to-do list and goal tracker app
everyday.app - Every day, it gets a little easier. But you gotta do it every day, that's the hard part.