iOS (iPod, iPhone and/or iPad)

Symbol-based

Asterics AAC
TD Snap: commercial, with a Catalan synthesised voice. Free version without voices.
Grid for iPad: requires a commercial licence, available in two forms, monthly subscription or one-off payment. The monthly subscription version can be tried free for one month.
JoComunico: requires an internet connection.
Verbo 2: free download; the full licence is paid.