GemmaGriffin
iPF Noob
Don't know if this will work for everyone, but I found that if you close the app completely, you'll gain energy when you're not playing without having the app open. To close the app completely, exit the app by tapping the home button once, then double tap the home button, press and hold the icon of the app at the bottom of your screen, then press the minus sign in the red circle. It has worked for me every time.