Habit List - Create good habits and break bad ones with the app that keeps you focused.
Habitica - Habitica is a free habit building and productivity application.
Momentum - Agile goal and performance management
LifeRPG - Automatically prioritize your goals and gain XP for achieving them. Features:
everyday.app - Every day, it gets a little easier. But you gotta do it every day, that's the hard part.
Coach.me - Coach.me is a coach that goes everywhere with you, helping you achieve any goal, change any habit, or build any expertise.