iOS (Jailbroken): One of the most annoying things about installing and updating apps on an iPhone is that you have to reenter your password every time. This is an understandable problem, as it's more secure to ask you, but it would be nice if there were an option to avoid it. If you're jailbroken, there actually is.
Password Pilot is a free tweak you can find on Cydia (the jailbreak app store) that will remember you password, keep it encrypted, and enter it for you automatically whenever iOS requests it. That's all it does, but it's a relief to have it remove that one, considerable annoyance. If you want to support the developer and gain a few more features, you can also find Password Pilot Pro on Cydia for $US2. It will let you customise when your password is filled in and when it should be left blank.