Africa has produced a number of insanely successful start-ups, though mostly not in the tech area. e.g. De Beers is dominating the diamond market worldwide & was founded in South Africa. Same for Anglo American PLC.
On the tech side there is Dimension data. They are in talks regarding a take-over for 2bn pounds. MTN Group is operating in 21 countries. Then there is Mark Shuttleworth's startup Thawte consulting. Sure, none of those are on the scale of Google, but given the circumstances its not bad.
I'd also like to point out that this part is deceptive "110 million connected online (growing in triple digits)". Being connected in Africa does not mean that the connection is really usable. Its expensive & slow and has only been really improving in the last year or so.