Bored working out with a heavy bag by yourself? The Bag Zombie app will make your heavy bag become "undead" (not alive like a real sparring partner, but fun as in hunting down zombies.)

The app calls out punch combinations at random times. You can configure the punch combinations and round timer. When your glove hits the bag, it makes a loud bang sound. The app listens for that bag with the phone's microphone. Based on your reaction time, your receive live feedback over the speakers. You can also analyze your punching patterns after the round.

Note: You'll need access to a heavy bag, a quite workout area (for precise punch sound detection), and headphones (to avoid sound feedback).