Speech impediments can hinder a person's ability to communicate, but it doesn't have to mean that they have to struggle. There are plenty of resources to help them in their daily activities.
Verbally is a text-to-speech app that helps people with speech disabilities to speak with ease through their iPad. You simply type in what you want to say, and Verbally speaks it for you.
The app has several grids with commonly used words and phrases. This makes typing the exact sentence you want much quicker.
You can add your own commonly used phrases or have Verbally analyze your conversations to find your most-used words.