I think the “Fighting Fantasy” books which I grew up with could make a pretty big come back in the eBook era – essentially they become a text based game.
The issue become being able to run it on the device. You could either write a framework for these devices, I don’t know if any of them are android based, but you might be able to get away with using ePub and whatever native software reads it. So long as you can get to a random page, you can do everything based on that. For example, the current Fighting Fantasy books allow you to flip through the pages and stop on one instead of doing a dice roll – there are two dice down the bottom of each page. For character creation you could have a bunch of characters pre-made and it just randomly chooses one…