The ubiquity and universality of smartphones make them ideal fog devices to bridge edge devices and the cloud. However, to support a wide range of applications, as well as adhere to the resource constraints presented, the software stack on smart phones needs to be reliable and adaptable. We propose RAINA, an architecture to enable reliability and adaptability in Android. While our work is on Android, our ideas can easily be adapted to other mobile OSs. This article describes our software architecture, systems challenges, application challenges, and methods to address these challenges. We also discuss future work to allow smartphones to truly be at the center of the fog.