Probably the best place to start on AppsForAAC (AAC: Augmentative & Alternative Communication) is by browsing the Full List of apps organised by category, speech system and symbol system used. For more information on a description of these categories and more information about this sites reason read the about page. You can also compare apps by clicking on the "Add to compare" link at the side or bottom of each app. Once you have added a few then just visit the App Comparison page to view your apps side by side.
Children can communicate through text to generate digitized speech for face-to-face interaction. Provision to write and edit documents, browse the Internet, play music and games, and control household appliances like TV and DVD.