Android Workout Apps?

Orkydd

So, I have a rooted Kindle Fire and I came across in the amazon market some apps called Daily Leg Workout, Daily Ab Workout and Daily Arm Workout and I've got to say they have been wonderful. They have different intervals you can choose from and the exercises don't ruin my back but still make me feel like I worked my tooshy off! Anyone know of other apps out there that are similar? I have the P90X dvd's but I tried them before and they caused me to hurt my back and I never used them again.