One of the mMoney opportunity with a big potential business for mobile apps is Mobile payment system in Africa.

Example with M-PESA which was introduced by Safaricom in Kenya in 2007. It is a mobile payment system based on accounts held by the operator, with transactions authorised and recorded in real time using secure SMS. Retail stores are paid for converting cash into electronic value, and vice versa. After two years of operation, the amount of retail outlets had surpassed the number of post offices in the country and currently represents a network of 39,000 retail stores. At present, M-PESA has approximately 15 million customers and contributes with 15.8% of Safaricom’s revenues.
Sources gsma.com (page 55 on http://www.gsma.com/publicpolicy/wp-content/uploads/2013/01/gsma_ssamo_full_web_11_12-1.pdf)