Viewing images is easy - just touch on the "disclosure" triangle for the image on the main (library) screen. The develop screen will then open with the selected images displayed.
Zooming and Panning
You can zoom and pan on the image with all the usual iPhone/iPad gestures - two finger pinch or multiple tap to zoom in and out, single finger stroke to pan.
Displaying the HUD
The HUD allows you to adjust various image parameters - exposure, contrast and brightness, as well as to rotate the image, and create a JPEG.
To display the HUD, simply tap once on the image area. Note: you must tap on the active image; tapping the surrounds will have no effect.
To hide the HUD, simply tap once.
Returning to the Library view
To return to the library view:
Display the HUD (if not already displayed) by taping once on the image
Touch the Return button on the HUD.