From Matt Fargo:
Tablet Tennis is an iPad-era version of Pong. Rather than moving your paddle, you draw the paddle with your finger. The smaller you can manage draw your paddle, the harder you will hit the ball.
Hit blazing down-the-line winners or slice odd-angled balls crosscourt. Tablet Tennis really feels like playing tennis with your fingers.
You can place your iPad, iPhone, or iPod on a table and play against a friend, or challenge one of the computer opponents.