I think it’s something like Muun wallet. An extremely simple app that anyone can download for free, setup with just an email as backup and use immediately. Send, receive and balance display. That’s all granny can handle and that’s all a non-technical user really needs.
Discussion
Muun is great, but think even simpler!
Think for somebody that has trouble using mobile apps on a smartphone.
The only simpler evolution I can think of is an inbuilt wallet of some kind that comes pre-loaded in the OS of smart phones. But getting funds into the wallet would still be a hurdle for the challenged user.