More information here: https://itunes.apple.com/au/app/proloquo2go-symbol-based-aac/id308368164?mt=8
Proloquo2Go is an award-winning symbol-based communication app that gives a voice to those who cannot speak. Over 175,000 people already use this AAC app as a powerful tool for expressing themselves and increasing their communication skills and language development. Its innovative features let users, parents, teachers and therapists quickly personalize the app.
Proloquo2Go is an AAC (Augmentative and Alternative Communication) app used by people with autism, Down syndrome, cerebral palsy and other diagnoses. It is available in English, Spanish, French, and Dutch for iPad, iPhone, iPod touch and Apple Watch.