People that have speech related accessibility needs will tend to rely on the text-based features of phones to help them communicate effectively.
The GARI template includes a section outlining which messaging options are available on a given model. These options may include:
- Text Messaging/SMS
- Instant Messaging
- Multi-media Messaging
- Predictive Text
Another feature that may be useful is the ability to personalize a SMS message so that you can re-use it as many times as you like. "On my way home now" is the sort of personalised message that many people would be able to use and re-use.