ABC Keyboard
This is a change to what you are used to in a keyboard: a keyboard layout that's entirely alphabetical.
From the App Store listing:
DyslexiaKey
Where the previous iOS keyboard app was iPad-only, DyslexiaKey works on the iPhone. From the store listing:
Lowercase Keyboard
Apple Distinguished Educator, Matt Thomas, has made a custom keyboard for iOS8, using OpenDyslexic. Below is the description: