FlipClock is a free and open-source Android app that displays a clock on your phone. There are no ads or permission requests. It can be used as a screensaver on older, unused Android phones.

It is designed to be used as a lock and home screen background clock. You can also set it as a widget on your home screen.

The app has an in-built time zone database. It supports both 24- and 12-hour time formats. The app has an option to display the current date and time.