If you're looking for a fun way to prank your friends or family, the Mouse on Screen Scary Joke app by Just4Fun Animals is perfect for you. This free Android app displays a realistic animation of a small mouse on your screen, which walks and squeaks around your phone's display.

To use the app, simply press the "Show Mouse" button and grant the app permission to draw over other apps. The mouse animation will then appear on your screen, visible even when you're using other apps. You can adjust the size and time delay of the mouse, and choose between top and side views of the rodent.

This app is ideal for anyone who loves to play pranks or make jokes. Whether you're browsing the internet, using social media, or playing a game, the mouse animation will be visible on your screen, adding an element of surprise and mischief to your day. If you want to remove the animation, simply press "Touch here to remove Mouse" in the Android top notification bar or run the app again.

Overall, Mouse on Screen Scary Joke is a fun and entertaining app that is sure to delight pranksters of all ages.