With the Windows printserver you can use every printer. Note: the image output format (1240x1844px) is optimized for a full bleed print on 4×6″ size (as used for dye-sublimation printers).
For the printserver to work you need a LAN network (router) and a Windows computer.
The app works on every iPad. It is recommended to use the newest iPads for the best image quality.