Another phone app that is available to Nigeria users is epenpal, though I think I am right in saying that this is android only. I have a friend who met his fiancee on this app, so don't be fooled by the name. I know you are able to filter by country and gender (also age) and can start chatting on the app then move to easier methods (kik etc) when you feel comfortable.
On the internet check out interpals, that's another good site where although generally thought of as a friendship site, has many people looking for relationships etc. Again you can filter by country, age, gender etc.
I hope that helps.