Battery Control lets you show/hide battery and battery percentage on your 3.0 device, when you install this app you wont see any icon on your springboard, because its a Settings toggle and you will find it in Settings. To navigate to Battery Control: tap Settings>Battery Control.
Once you reach there you will see the option hide/show battery and battery percentage and Donate via PayPal option (if you like it this tweak then you can donate as well :P).
Battery Control is available for free under modmyi repo.