Hack for kids: instead of an unrestricted access to a tablet, give them a walkman with cassettes. They get understanding of physical medium, they can record songs they like (even from YouTube), stories, ... Modern walkmans can record from analog audio input, some have even an integrated microphone. They have fun, they can play and it's entirely their own thing. On the other side there's no corporation wanting their attention to fill their head with cornflakes ads. And then you give them Bitpunk.fm cassettes to listen to some good music (e.g. Deepologic) and they also learn about Bitcoin and analog encoding and a lot of other stuff. If you don't have the cassettes, you can even make them from the digital version yourself! Just start a v4v player like fountain, press record and flip the tape when the time comes.