GoalsWon - Human accountability coaching for busy people
Habitica - Habitica is a free habit building and productivity application.
CARROT - Meet CARROT, the to-do list with a personality.
Loop Habit Tracker - Loop Habit Tracker (AKA uhabits) helps to create and maintain good habits in order to achieve their...
Beeminder - Beeminder
ActivityWatch - Log what you do on your computer. Simple (yet powerful), extensible, no third parties.