The mobile app economy was worth $53 billion in 2012, and the forecast for 2016 is that it will grow to $143 billion. The figures vary slightly from researcher to researcher but the fact is that mobile is really big. Revenue is generated through in-app purchases, in-app ads, and big data accumulation. The most promising sections are social networks, utility, advertising, and productivity. The fastest growing markets are APAC and Latin America.