I use apps quite a bit in therapy. They are a lightweight way to carry a LOT of therapy materials (a tablet vs a shelf of books and stacks of cards). They are great for home programs because they can provide auditory models. BUT, I still use writing vs typing for many of my clients and incorporate writing into the communication tasks.
National Public radio helps explain why:
Writing, and taking notes, is not only helpful in supporting communication, it also helps the brain process and retain information - essential for recovery from brain injuries.
Reading the book "The Right to Write" by Julia Cameron this summer helped strengthen for me, how important writing is. Not just at a function level, but from a brain standpoint.
Practice for anyone (whether you've had a brain injury or not):
Next time you watch a TED talk or a TV show, take notes. Write down key words, anything that seems important. Then use those notes to have a conversation with someone about program.