Compatible with iOS 4, 5 and 6
Convert your standard resolutions App tore apps to retina display with a press of a button !
You only need to open the iRetiner app and click the "Adapt icons to Retina Display" button to adapt icons to retina display and click the "Revert to original icons" to switch them back to standard display.
Note that the app will respring your iDevice on iOS5
See Hi-Res Screenshots below