Augmented reality has in recent years become very popular in commercial areas such as entertainment and advertising. The fastest growing field right now is augmented reality for mobile devices. This is because the rapidly increasing performance can manage the heavy operations which only desktop computers used to handle. So far traditionally standard markers have been used, but in this paper we will take a look at a different technique, natural feature tracking. The final product will be an open source augmented reality API for Android freely available online.