Alexicom AAC - Communication App available for IOS (iPad & iPhone) and Android, with external switch support.
BoardMaker V6 - A flexible and powerful communication display maker. BoardMaker is a graphics database with 3,160 Picture Communication Symbols (PCS) in clip art form.
ChoicePad Lite is an iPad App that features Makaton symbols.
Clicker 6 is compatible with Clicker 5 grids and has built on the strengths of the previous versions.
Communicate: In Print 2 - A desktop publishing program for creating symbol-supported resources for printing.
Communicate: SymWriter - Word Processing with Symbols
FreeSpeech - A pretty good free communication App.
Gabby - A cheap, yet effective communication App for the iPad, iPhone and iPad Touch
Grid Player - iPad App from the makers of The Grid 2, bringing their take on a communication App to the tablet market.