[johncole]

Ah one more hack or idea. My kids LOVE books. Our local library has the Libby App and we get tons of free books for car rides and nap time. Get it and get them a kindle fire. Then completely disable games and only enable books.

[HenryBemis]

You can root a Fire, change its launcher, disable the bloatware, install the PDF/epub/etc. reader of your choice, and you end up with cool tablet-readee that has battery for days!!! I kept mine offline and copied the files I wanted through PC, so I also never had to worry about security or upgrades.