In this paper, we propose a lightweight mechanism to isolate one or more Android userland instances from a trustworthy and secure entity. This entity controls and manages the Android instances and provides an interface for remote administration and management of the device and its software. We provide an administrative solution for dynamically modifying, removing or adding multiple Android instances remotely and locally. Furthermore, we present a secure device provisioning and enrollment solution for our system. Our approach includes several security extensions for secure network access, integrity protection of data on storage devices, and secure access to the touchscreen of mobile devices. Our implementation requires only minimal modification to the software stack of a typical Android-based smartphone, which allows easy porting to other devices when compared to other virtualization techniques. Practical tests show the feasibility of our approach regarding runtime overhead and battery lifetime impact