4 stars: Loop - Habit Tracker apk download - Simple. Powerful. The best habit app I've found. Don't expect magic. Instead read/skim (a summary of) the book The Power if Habit if you want to understand and take control of your own habits. Features I'd like to see in the future: 1. Automated backups for download Loop - Habit Tracker apk and sync. 2. When importing previously exported data, I'd like a warning and/or choice to merge or overwrite existing data. Currently this overwrites existing data without warning. That's too bad when you expect a merge instead. 3. Instructions on how to come up with maintainable habits and how to review them. 4. Smart import merge...