The TapSpeak series

http://tapspeak.com/drupal/

There are three apps in this series. TapSpeak Choice allows you to make pages for communication. TapSpeak Sequence is for timetabling and other sequencing and TapSpeak Button is a single button that you record a single message one. You can store your single messages for retrieval as often as you like. TapSpeak uses Meyer Johnson Picture Communication symbols.