There is quite a lively tech scene. One example of an interesting all-African startup is Africa's Talking (http://africastalking.com).
If you're looking for a problem to solve, one thing I struggled with when living there is that there is a major lack of trust between renters and landlords when it comes to housing. Some landlords are ok, but many arbitrarily withhold money from the initial deposit when renters move out and I feel like that generates quite some inefficiency in the housing market. I'm not sure what the solution would be but I know many people would benefit if there was one :)
If you're looking for a problem to solve, one thing I struggled with when living there is that there is a major lack of trust between renters and landlords when it comes to housing. Some landlords are ok, but many arbitrarily withhold money from the initial deposit when renters move out and I feel like that generates quite some inefficiency in the housing market. I'm not sure what the solution would be but I know many people would benefit if there was one :)