In this paper we introduce JustSpeak, a universal voice control solution for non-visual access to the Android operating system. JustSpeak offers two contributions as compared to existing systems. First, it enables system wide voice control on Android that can accommodate any application. JustSpeak constructs the set of available voice commands based on application context; these commands are directly synthesized from on-screen labels and accessibility metadata, and require no further intervention from the application developer. Second, it provides more efficient and natural interaction with support of multiple voice commands in the same utterance. We present the system design of JustSpeak and describe its utility in various use cases. We then discuss the system level supports required by a service like JustSpeak on other platforms. By eliminating the target locating and pointing tasks, JustSpeak can significantly improve experience of graphic interface interaction for blind and motion-impaired users.