Why the downvotes?
Mpesa was made for a VodafoneUk subsidiary. It's not network ubiquitous(& hasnt scaled as succesfully in other vodafone subsidiaries) but makes a lot of profit for its network.
Ushahidi is OS & not-for-profit & has shown "growth".
ps: I use Mpesa regularly and I've tried Ushahidi, they both 'fill a need' but differ on scaling & revenue.