InstaSave is a tweak released during this night in Cydia, and with its help we can quickly save photos from the Instagram application in the Camera Roll. Normally the Instagram application does not allow users to do this, but only to upload pictures from the Camera Roll application, but this tweak also implements the reverse functionality, so any picture you view in the Instagram application, you can save it directly to your iDevice. InstaSave is available for free in the BigBoss repo Cydia and is compatible with iOS 6.
