I think Bitcoin can help poor countries (concerns indigenous people also I think) in many ways. For example, giving your bitcoin savings to the country, withdraw it to physical money to donate them. Also, to help the country more, we could help them by turning them to technology. Teaching them what the use of a Personal computer, what are the advantages of the internet. We could help them cope up with the various technology we have, even the simple ones. The small things can help them in a big way. We don't know how they really are, but helping them even in small things matters.
Donating money might help out certain individuals, but that's the only effect it will have.
Plus, in order to make some sort of an effect, you need to continue donating, otherwise they will run out of money in a quick fashion. But I personally don't see donating money to the poor as a solution.
Especially when you are donating to well known charities that are paying staff, rent, spending good money on advertising, and the list goes on. From every donation a tiny amount will actually go there where it's needed.
Investing in proper education and possibilities for people to start up a company is the first start. I think that has much more effect than donations will ever have.