I have ipod touch 2nd generation to play the game. It has no backgrounder. Even if it has, there is not enough memory to open 2 apps at the same time. So every time I try free plantium, the game app will quit. Then go to download page -> download -> open new app -> go back to game app.

Only about 1/4 chance I can get 1 free plantium, but every time the free app disappeared even if I got nothing from that. Is this a bug or something?