As mobile development has matured, mobile developers have had to broaden their sights. When the first mobile apps came out, there were not only very few rules but also very few capabilities. As mobile software evolved, it became part of a larger whole. These days, mobile developers can't afford to think just about the device itself. They have to also think about how it fits into a broader ecosystem: back-end systems, privacy implications, network capabilities, scaling, and security. This report describes what mobile developers need to know in the context of that larger ecosystem.