My Mother had several small strokes and has right-side numbness and a bit of right control issues. She also experiences memory and confusion issues that are exaggerated when fatigued. Prior to her stokes, she loved to journal an write cards & letters. I would love to learn about "Senior" Apps or programs.
If they have more severe communication issues there are programs that use pictures and symbols to create sentences and the translate into written word. The specialist would be more able to help after meeting with you and your LO.
To find someone, you can go online and Google eldercare and assistive technology and look for a regional locator.
In several different situations I have seen families buy CD players and iPads for their elderly loved ones with the confidence that their loved ones will love it once they get used to it. But not once have I ever seen an elderly person able to use the Tablet, iPad, or CD player on their own. They get overwhelmed and put it aside and never use it.
I bought my dad a portable DVD player and some of his favorite movies. The DVD player had 3 options: on/off, play, pause. I went through it with my dad and he ooh'd and ahh'd over it, seemed to like it, but left to his own devices he put it on the floor and turned his tv back on. He never once used the DVD player.
The family of an elderly lady in a nursing home bought her an iPad because she had seen her family using one and expressed some interest in it. Once the lady had the iPad she didn't want to touch the iPad so someone had to be with her and encourage her to use it. She wouldn't use it herself and her family realized that they could have just used their own iPad since this lady didn't want to touch her newly purchased iPad. She had dementia and it was too overwhelming and frustrating for her. I suggested to the family that they take it with them when they leave but they thought that the lady might use it when no one was around. Within a month of buying it not only did the lady not want to use it but it was stolen right out of her room.
I hate to sound like a Negative Nelly and I'm sure there are some exceptions but I've never seen an elderly person with dementia successfully navigate new technology. Most have difficulty just using cordless phones and remote controls that they've been using for decades.