App Development Advice

Wish to discuss app development. Need to be able to integrate mobile payment system into app Such as M Pesa. For use in developing countries particularly the African continent. Also wish to discuss integration of of Global Positioning System in map such as Google maps. App would have similar function to Uber in that you can see where you are, see where someone else is and monitor movement in real time then make a mobile payment. I would like to know what's possible and approx. quote to build after more discussion would be helpful.