Greetings! We have a new app approved on Apple's App Store.
http://itunes.apple.com/us/app/lens-lab/id431559363?mt=8
It's called "Lens•Lab". Here's a description:
Lens•Lab is a virtual lens simulation tool for photographers of all skill levels. It graphically illustrates how depth of field and field of view relate to your SLR camera and lenses.