PW2 Pull new screensaver from net on power on?

Hello.

My grandfather needs to check some data daily. This is proving very hard for him as he gets older. I would like to modify a Kindle that would help him with this task.

Would it be possible to mod the kindle PW2 (or can buy some other version) so that it wakes up every 4 hours, pulls an image from the internet, sets it as screensaver and then turns off.

Or alternatively when the power-on button is pressed it pulls the image, sets it as screensaver and shuts off?

Is this possible to do? Where can I start? Any good resources to check? I can program but no idea on what is possible and what not on the kindle nor how to setup a dev env for the kindle...

I think this use case would be good for other people too, so maybe it laready exists?

Thank you for all ideas and advice in advance :)