There is stuff out there.....
I'm a paid up member of AARP and their magazine regularly features adverts for simplified phones and computers. The phones -- smart or flip -- feature a thinned down user interface and larger buttons and icons. Similarly the computer they offer is an all-in-one that has a reduced subset of applications, again with larger icons.
I don't know how good any of this stuff is; its a bit gimmicky for me (and I'm not *that* old!). But its a starting point. It also points to one of my pet peeves about modern applications software -- too gimmicky, too fiddly, too bulky and too buggy.
Biting the hand that feeds IT
