In recent augmented reality (AR) application, marker-less tracking approaches are often used. Most marker-less tracking approaches force user to capture the front view of a target object during the initial setup. We have recently proposed two image rectification methods for non-frontal view of a planar object. These methods can be applied to reference image generation in marker-less AR. This paper describes a pen based tool for annotating planar objects. Our tool builds upon several interactive image rectification methods, and supports registration of AR Annotations, marker-less tracking and annotation overlay.