Habitica - Habitica is a free habit building and productivity application.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Coach.me - Coach.me is a coach that goes everywhere with you, helping you achieve any goal, change any habit, or build any expertise.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
SuperBetter - Empower youth mental health through schools and sports
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.