Africa is uneven in its (under)development. Your part of Africa is less well developed than say, Cairo, Johannesburg, Lagos etc and yet huge opportunities exist in these areas. If you are entrepreneurial (and I strongly urge you to be) there's a goldmine sitting unexplored at your feet right now, and all you have to do is start digging.
A few suggestions.
In my country a couple of years ago, students who wrote their high school exams had to go and check their results on a physical board at a designated site. Someone came up with the idea of having all the results posted online as well as digitizing the enrollment process. The students pay the equivalent of $2 to use the service and almost a million enroll every year.
Think about the process of registering a company in the Congo? Could you migrate it online? What about searching for real estate title documents? School management software? Sundry government processes? There are many possibilities. I have no doubt that these same problems and more exist in the Congo.
I am presently working on an idea similar to those listed above (cant say anymore at present, many Nigerian developers visit this site! competition!) and it shows a lot of promise; I can assure you that there are many similar opportunities waiting to be exploited by skilled people like you.
Look inward. Look downwards. At your feet. For the goldmine.