Play your movies on your iPhone and simultenaously on an external display with full control of the projection geometry(aka keystone). This is very useful for pico projectors or whenever it is not possible to modify the hardware projector configuration. Ideal for road warriors. Requires a "Apple Digital AV adapter" for the external connection. Also designed for the AV adapter you can also use AirPlay to send video to an Apple TV.
You can play movies from your photo library or from your iTunes library (limited to non cloud stored and DRM free media).
On top of the keystone correction, TheProjectionist allows you to flip the external display horizontally and vertically. This allows a correct projection when the projector is aimed at a mirror (horizontal) or when the projector is attached upside down on the ceiling (vertical).