This is one of the most unique Halloween apps we've seen. It combines a fun game with exercise. The app is called Zombies, Run! The game takes place after the zombie apocalypse. You are a runner, tasked with running and grabbing supplies and bringing them back to your town.
You start up the app as you go for a run, the farther you go, the more items like medicine, batteries, and ammo you collect. After exercising, you use the supplies you've collected to improve your town by constructing new buildings and defenses. Zombies, Run! comes with 30 different missions, Zombie chase interval training, audio tracks that reveal the plot between your music, and more.
Zombies, Run! will set you back $7.99 for the full version. There is a 5K trainer version for $3.99. It is available for download on the iPhone.