IconRotator 1.0 is out and I attest it works on a 4S with 6.1.1 (v0.2 did not.)
I had been using IconRotation in the meantime, but I find IconRotator superior for two reasons:
1. It handles the upside-down portrait orientation.
2. It rotates the icons at a reasonable screen angle. With IconRotator I had to turn my phone nearly horizontal before they would rotate.
Of course, I'd really prefer SBRotator, which I have purchased, but even the latest version (6.1-20) still has issues with FolderEnhancet. (Icons in folders get stacked on top of each other in landscape mode.)