I second the shock absorbing case. We got this one. It bounces.
Apps that are used most frequently by my 2yo and 3yo:
Tozzle
Balloonimals
Baby Scratch
Talking Tom (and its many, many varieties, often free - Talking Ginger has been particularly good)
Dipdap has been very popular
Cbeebies
any Duck Duck Moose apps - I have Old Mac, DH has Incy Wincy Spider and the Wheels on the Bus, and my DC have played with others on the Apple store iPads
Cars, Planes & Trucks Pairs (any sort of flashcard matching games seem popular)
Baby Colors
ABC Song
Balloon School
Kids Songs
Farm School
I've also downloaded several Cbeebies shows, which my kids play regularly.
Get some of his favourite stories. There's often an app version, or could be downloaded as audiobooks for him to listen to. If you show him where to find the videos and audiobooks a few times, he'll have no trouble navigating to them on his own in no time!
Be sure you set the restrictions so he can't install, delete, or do in-app purchases!!!! You can also remove the internet browser.
I hope your little one gets well soon and the hospital visits go well! 