Purp - A smart to-do list and goal tracker app
Streaks - The to-do list that helps you form good habits.
Things - Things is an easy to use task manager.
Gone - An ephemeral to-do list
Nirow - Habit tracking: Automated, Siri-ed, Calendar-ed, and More!
The ToDon't List - A to-do list for avoiding the things you shouldn't be doing