A lot. My parents and I recently bought my 93 yo Grandfather an iPad, and even though he's smart and has owned a desktop mac for 15 years he still struggles with things like email and photos on the iPad. Senior-oriented features/ui, and maybe family remote control help, would be neat. It's also possible that 93 is just too old for some people to learn new technology.

Tangentially relevant: watching a nontechnical senior citizen use an app I worked on was a humbling experience. Things that seemed obvious to me were disorienting and discouraging, even after patient explanation that could never be offered in production.