So I am wondering if there are any games similar to pokemon on the app store. I really don't want to have to go and buy a ds, since I have an iTouch. Any suggestions will be appreciated very much, thanks in advance.
Sorry but there really isn't. There are games with sorta similar graphics, but nothing where you go around capturing and battling monsters - to my understanding. However you can get emulators if you are jailbroken/unlocked. Emulators are apps that let you player SNES, NES, GBA games and stuff on your device. It's only legal to play a game on the emulator if you own the actual game though.
No you can't. As far as I know, there isn't even a decent DS emulator for OSX yet, let alone the iPhone.