User input has taken many forms since the conception of computers. In the past ten years, Tablet PCs have provided a natural writing experience for users with the advent of active pen input. Unfortunately, pen based input has yet to be adopted as an input method by any modern mobile operating system. This thesis investigates the addition of active pen based input to the Android mobile operating system. The Android input framework was evaluated and modified to allow for active pen input events. Since active pens allow for their position to be detected without making contact with the screen, an on-screen pointer was implemented to provide a digital representation of the pen's position. Extensions to the Android Software Development Kit (SDK) were made to expose the additional functionality provided by active pen input to developers. Pen capable hardware was used to test the Android framework and SDK additions and show that active pen input is a viable input method for Android powered devices. Android was chosen because it is open source and therefore available to modify and test on physical hardware. Gingerbread (Android 2.3) was used as the code base for this thesis. All modifications to the Android framework that are detailed in this thesis will be made available online. The goal of this thesis is to explore methods of integrating and exposing active pen input in Android and encourage the implementation and adoption of active pen input by Google as a standard input method in Android.