Calendar is a free reminder app for Android developed by Alexander Barbyshev. The app provides an easy way to create reminders and color-codes dates for events. It also offers sound and vibration alerts for scheduled events.

One of the best features of this app is its support and development. The app is constantly updated, and the developer takes the users' wishes into account in the design. The app is a complete analog of the paid application "Calendar Pro" except for the presence of advertising. If you like the free app, you can support the project by purchasing the paid version.

In summary, if you are looking for a simple and effective way to create reminders and color-code your events, Calendar is a great choice. It's free, easy to use, and constantly updated with new features.