Check out the resources I have on the other grades pages. A number of those resources are perfect for your students. However, I'll add a few more tools/resources here for you that could provide your students with more success/independence.
Braille Keyboard. Yes, I clearly know that Siri can do voice to text just lovely. But, it would be helpful for visually impaired students to learn how to use the Braille Keyboard. So, the iPad has one. And, yes, the iPone has it as well.
Speech-to-Text. Google Docs and Microsoft Word both have a speech-to-text tool. If a child has an injured hand/arm this is great for temporary situations like that. Or, if your students have severe difficulties with letter identification, but you want their thoughts on "paper" this is a splendid tool to record their ideas. Add an image. Print it out. Post it on the wall. "Look, Mom. I did that!"
Microsoft Word. Put anything you want to Microsoft Word and click the Read Aloud button. Bam! Just upped your game. Anything. Read aloud. Anything. Enjoy!