[Nexus 7 Q&A, Help & Troubleshooting] slack04:
You're probably not going to like my answer, but I tried this (also with a person who had use of only one arm) and it didn't work. I mounted it to a table on a movable arm to make it easy to use.

Beyond the shaking hands and weak eyes, the biggest problem is understanding the UI. To you and I it's not complicated, but we grew up with computers. That's not any sort of judgment; the guy was capable of using a windows XP computer (very very slowly), it's just that switching to a new IU is much more confusing to the older brain than for a younger brain. They just don't have the filters to pick out the important information from the screen quickly, and every step requires conscious thought. This can be very tiring for an older person, and--at least in my experience--older people don't have a lot of tolerance for frustration.

I don't want you to be discouraged by this; I spent weeks on this (and several hundred dollars) and ended up getting him a small laptop on which I installed a simplification program that allowed only basic email and internet. But your relative may be more savvy, have better coordination, or just more interest in making it work. Here's what I'd suggest:

1) "minimalist text" can be customized to put static text on the screen. You'll have to play with it a bit.

2) There's no applications I can think of that make it easier, but I'd suggest giving her some system to mount it where she can both see and reach it. Have her sit as she would when she wanted to use it (chair, table, bed) and figure out how she can use it with her arm resting on something.

3) I think the picture frames widget is included in stock android. I'd strongly suggest against using anything other than a solid-colored background though. Again, it's difficult for an older brain to parse large amounts of information, and older eyes to see past the contrasts. I'm sure there's some way to have a rotating photo widget on some part of the screen in the market though.

4) Swiftkey. It's a bit advanced, but has one major advantage: predictive text. She can enter a few letters and the software will come up with a few words. Often it will get the intended word within a few letters, which can save a lot of inputs. That said, I think the stock android keyboard in JB has this functionality too, so you might hold off and try that.

A few other suggestions:

1) Get a launcher that can be cut down to just one screen. ADW EX does this. And get rid of the elastic screens (allows it to stay static). You said you already have a custom launcher in mind; which one were you thinking of?

2) When AOKP gets their hands on this, they'll allow you to add and change buttons to the notification bar. Get rid of the long-presses, maybe even get rid of everything but the home and back button.

3) Forget the speech recognition stuff. Old voices are not easy to understand for anyone, much less a computer, and convincing an older person to speak slowly and annunciate is not easy. Also, the first time it doesn't work you'll have a very frustrated relative to deal with...

4) Keep it simple. The first time you show her how to use it pick one thing (probably email or video chat) and show her how to do just that. If you take just one suggestion from me it's this. Add something next time, once she gets how to do email or video chat (test her first). Seriously, everyone will end up happier as a result.

OK, good luck! Hope it works better for you than it did for me!