An Apple patent filed back in 2009 shows the Aperture app running on a larger touchscreen -- something akin to the iPad, though of course back then it didn't officially exist yet.



From TUAW:

Apple hasn't released that app for iPad yet, though it has released a few iWork apps and even a pretty comprehensive version of iMovie on the iOS platform. The iPad didn't even have a camera at launch, but now that there is a camera in the iPad 2 it's possible Apple could be putting together a high-end photo editor for the iPad's touchscreen.

  Patent shows Aperture on iPad