The process is a very straight forward one but might be length depending on your current position.
First agenda will be to establish if you are a programmer and if yes, can you build all the game by yourself.
If the answer is no, you will have to find an individual or company that will build it for you.
(This also leaves the room for question like, who is going to cuff up the bill. Will it be you or will someone sponsor it)
After the initial App is up, you or a dedicated team needs to maintain the app on a daily bases.
And finally marketing if you targeting the whole of Africa, that is a lot of marketing that will need to be planned. But on the off chance your app is something that is needed withing the African communities, it will end up selling it self.