Mårten is the author of Runtime Resource Overlay (RRO), a feature in the Android framework which allows the injection of additional resources in running applications. This can be used as the basis of higher level features such as Android themes or device customization. Mårten has been involved in Android since it was first made available outside Google. Over the years, the main focus has been on the Android framework. Today, Mårten is involved in the advancement of RRO and the Android Open Source Project.