FolderInFolders is a Cool Tweak from Cydia for just $1.99. It allows you to make Folder in Folders. Did you ever get frustrated about the fact that the new iOS 4 only allows only 16 apps in one folder. Now with this cool Tweak from Cydia (Needs Jailbroken iDevice) allows you to make as many Folders inside a Folder. As you can see below I have a Social Folder inside which I have another Folder with Facebook, Twitter etc apps. (Tested on iPhone 4, works for all iOS devices).