A free app for Android, by AlcamaSoft.

Who says ping pong is a two-player game? With this fun, addicting application, you can now play ping pong alone using your android device. 

This app is called Circular Pong and the objective of the game is simple; toss the ball all around but make sure that you keep it inside the white circle. Once it escapes, the game is over. 

Try your best to make the ball hit the pusher at the edge of the circle to prevent it from leaving the circle. Tap the screen to keep the ball steady. The more you hit the pusher and the longer you stay inside, the more score you’ll earn.