I have a few tweaks installed. I think some tweaks only modify a plist somewhere while others like activator are probably running in the background and using up battery. How can I tell for sure which is which? For example, how much battery does f.lux use? I want to install a theme and change some of the ugly icons in ios 7. Does winter board runs constantly in the background to modify the UI? Or is it a one time application? Thanks.