I used to download a lot of apps for my iTouch, but inevitably I never really used any of them much except for ShoutCast and maybe the calculator in scientific mode. Most of the apps were a waste of time and money... which is pretty much the overall purpose of apps.
One thing that really pissed me off was a good wifi app that would actively and continually scan for wifi hotspots and log them and beep if they were open. It could even log into them automatically if you liked. It was very hackeresque smooth!!! It was amazing driving thru the local neighborhoods and seeing everyone's unencrypted wireless modems showing up block after block. That was actually useful for wardriving.
Sadly, apple forced the maker of the app to update without that wifi scanning function because it was some proprietary apple code that developers weren't supposed to use. Goddamn you Apple and all your proprietary bullsh*t.
Anyways, I didn't know about this when I updated the app so I lost my wifi scanner and there weren't any replacements available and i didn't have any backups.