Ryan Petrich has pushed an all new jailbreak tweak to Cydia called IconRotator. As the name implies, the tweak makes your icons rotate but in a pretty cool and smooth manner. Once you download and install this tweak, your iOS homescreen icons will rotate with your device. So when you rotate your iPhone to landscape, the icons will also rotate into that direction giving your springboard the look of a native landscape mode. The tweak is currently in beta and is available via Ryan Petrich’s personal repo.
You can try out IconRotator by adding the following repo to your sources in Cydia:
Watch IconRotator in action in the short YouTube video below: