Swiss Army Knife / App Box Pro
This app is an all-in-one of useful tools. Instead of downloading separate apps for a flashlight, a timer, stop watch, calculator and bubble level, this app has them all.
Swiss Army Knife: Free for Android Includes: A flashlight, unit converter, timer, stop watch, compass, bubble level, calculator, magnifying glass, mirror and ruler.
App Box Pro: $0.99 on itunes Includes a few more goodies in addition to those mentioned above: Battery Life, loan calculator, a secure wallet, tip calculator and an alarm clock.