Loop is one of the most popular free habit tracking apps, with its Android app clocking millions of downloads.
Loop is different from other apps in that it is open source. Its Github repository is available for anyone to fork and modify to their satisfaction, thereby allowing people with technical chops to make the app their own.
But Loop works great out of the box. It's got an extremely simple habit tracking interface where you can view all your habits at a glance, see how you performed in the last few days, and easily mark a habit as done, missed or skipped using taps and long-press actions.
The app also has cool analytics that lets you visualize your progress over time. What's especially great is the calendar view, which shows you at a glance which days of the month you performed or missed your habit.
All the data in the app can be easily exported as a CSV or a SQLite database file. You own your data completely.
Loop is available for Android.
This app is not available for iOS, Web, MacOS or Windows desktop PCs.
Loop is a completely free app. It is also available as an open-source repository on Github.