iMob is an awesome apple app, and its only 99 cents.  You can earn money doing missions, and battle online with friends and enemies.  People can join your iMob and make it stronger.  The only thing about this iPhone app is that you need energy to do missions, and you have to wait three minutes or so to regain energy.  Also, you need respect points to get special powerups, and respect points cost money.  Real money, from your pocket.