Normally, the keys of the iOS keyboard always display uppercase letters, regardless of the state of the Shift key.
With the ShowCase extension installed, when the Shift key is off, the keys will display lowercase letters.
This extension (or any such extension) will not work with apps that do not load MobileSubstrate, such as Cydia.
This extension is open source. If you find a bug or have a feature request, please try fixing/adding it yourself and submitting a patch via the project site.
(Tap "Developer\'s Page" below to visit the project site.)