Here is a site with lists of additional apps that can assist people with special needs.
I looked specifically at apps for the visually impaired, but there are many more app lists to look at on this site.
"One of Android's missions is to organize the world's information and make it universally accessible and useful. Accessibility is the measure of how successfully a product can be used by people with varying abilities. Our mission applies to all users-including people with disabilities such as visual impairment, color deficiency, hearing loss, and limited dexterity."