This tutorial provides a detailed introduction to mobile Augmented Reality (AR). AR is a key user-interface technology for personalized, situated information delivery, navigation, on-demand instruction and games. The widespread availability and rapid evolution of smartphones enables software-only solutions for AR where it was previously necessary to assemble custom hardware solutions. However, ergonomic and technical limitations of smartphones as a platform make this a challenging endeavor. In particular, it is necessary to design novel efficient real-time computer vision and computer graphics algorithms, and create new lightweight forms of interaction with the environment through small form-factor devices. This tutorial will present selected technical achievements in this field and highlight some examples of successful application prototypes.