> [...] how does having free internet benefit the continent?

I don't think it does. I think it's one of the ingenious ideas to solve social and infrastructural problems by throwing an app at them, because real solution requires work, while creating an app is cheap and still gives the author the feeling of trying to help the world.

> How does a poor person in a rural area REALLY improve their life by just having a cheap android phone and access to the internet?

Merely having a smartphone connected to internet is too little. To benefint from it one still needs to develop skills, and I can't think of anything that realistically could be done on 4" screen.