The epic western savior thing is very cringy and I don't know how to avoid it at his point in the project. I try to limit my role as much as possible

I think an important part is to figure out what is the best way to contribute. While it is good to let Tanzanians do as much as possible by themselves, they can't reach out to your friends. Only you can do that. When I tell my country mates about programmers in Africa, and I get a response like "They can do that?" with a big surprise impression on their face [1], I don't see how any African could do that by themselves. Bridges need to be built from both sides. If you remove yourself then you end up with half a bridge.

[1]: That was just one reaction I got when I told people about my work in Africa. Starkly contrasted by another reaction which was the opposite: "Oh cool, I am hiring devs in Ghana, they are awesome!". It's not all lost, but a lot of people simply still don't know. And that includes African-Americans.