This is a tutorial on setting up and running mobile phone orchestras. The participants will learn how to build the infrastructure that typical contemporary mobile phone orchestras use, will learn about the logistics of running such ensembles, and will learn about the technical underpinnings of varied forms of performance practices including mobile live-coding, audience participation, networked performances and more. We will also cover the basics of custom music app design using the urMus environment. urMus provides a live-patching environment for performance and rapid prototyping. This will allow participants to learn how to design and implement rich and complex interfaces that are useful and expressive for mobile performance. The course will be accessible to anybody who has a general knowledge of computer music. Prior basic programming experience and basic knowledge in sound synthesis is helpful but not required. We will discuss a range of performance by our ensemble to provide practical realizations for of the technical capabilities of mobile devices for musical ensemble performance.