Import images into the Alpha palette. Note that after tapping Select files... you can batch select files to import via the file selection navigator. Enable the Copy to Startup Folder option to place your alpha images in the ZBrush for iPad Startup folder (in addition to the default Alpha > Users collection) so that ZBrush will automatically see the file(s) every time it loads.
Also note that ZBrush for iPad allows you to batch import multiple alpha, brush, and texture assets, as shown below.
