Need more motivation to keep you running? Try having zombies chase you! This app creates a story-line that will require you to partake in interval training (walk, run, jog, sprint) that will get you into shape while keeping you entertained and immersed in a zombie-filled land.
I haven't tried it, nor do I plan on spending the $7.99 to do so, but it certainly looks fun. If I was a runner, I might give it more consideration.