21 Days is a free habit tracking app developed by appdevelopers.ru. This Android app is designed to help users keep track of their desired habits or to create new goals and celebrate their fulfillment. The app allows you to specify any deadline goals, and it will notify you at the right time. With its intuitive design, 21 Days makes it easy for users to work with the application and track their progress.

One of the most exciting features of the app is the ability to leave comments each time you run it, which is then displayed in the statistics of goals or habits. This feature provides users with a more personalized experience. The app also offers detailed stats on the created goals or habits, allowing users to see how well they are doing and where they need to improve. Additionally, there are several themes available in the appendix that users can choose from for a more enjoyable experience.