Android and iOS devices still attract the lion's share of developers because of their broad consumer support and bring-your-own-device (BYOD) adoption by employees. But they aren't the only mobile platforms in town. Other mobile platforms like Windows Phone and Firefox OS show growing developer preference in certain countries and among certain types of developers. The takeaway: Application development and delivery professionals (AD&D) should not lock their teams into policies that presume long-term equilibrium with only two platforms, especially if they build and support mobile apps in multiple countries.