In Pic-a-POD for iOS, when you tap the camera button to save a picture, it shows the following dialog (or something similar, depending on your device and configuration):
In iOS 5.0, tapping “Go to Settings” jumped to the Settings app, open at the “Brightness & Wallpaper” options, so you could immediately use the newly saved picture.
This was done using a custom URL scheme as shown in this page from handleOpenURL: although they do not list all the options, including the one I used: prefs:root=Wallpaper
However Apple has changed this scheme in iOS 5.1 so it no longer works. Hopefully they will be re-instating it or replacing it with something different, as I am not the only developer who used it.
In the meantime, if you have upgraded to iOS 5.1, this button will dismiss the dialog and then do nothing. It won’t crash or cause an error, but it won’t do what you expect.
I will be releasing an update soon that will remove this option for iOS 5.1 users – not a good solution but better than having a button that does nothing.