One of the major Problems in the current world is the low education in the 3.World.
Higher Education leads to a general improvement of the local society. Unfortunately a lot of poor families are not able to send their kids to a school, since either the next school is too far away or the kids need to work and have no time to go to school or it is simply to expensive.
Education starts with learning how to read and write. To be able to read makes it possible to take more education from books or the Internet.
A embedded very cheap device, that powers itself by solar and contains a software which helps the user to learn how to read and write by a sort of game could overcome the problem of low education.
The device must not be as advanced as a typical computer, it could be just a little bit more intelligent than an office calculator but not much bigger.
If it was so cheap and small, every kid could have one at home. The kid could use the device whenever she or he has time for it, for example in the early morning or in the late evening. Since the software designed to be a game, it is even fun for the kid to learn.