The 645 PRO is an iOS app designed by Jag.gr. “645 PRO has been designed, from the ground up, for professional and serious amateur photographers. So it works the way a camera works, not some piece of computer software.
Every setting is managed directly from the camera—no layers of menus to negotiate. You have instant access to everything that can be controlled, from focus/exposure and white balance locking to a 645 PRO-exclusive choice between spot and multi-zone metering.”
You can download 645 PRO from the iTunes store.