A promising application of GyroPen’s capabilities is as a method for text entry. Text entry on mobile devices is a topic of interest as mobile devices are getting more popular: entering text on mobile devices is still considered inconvenient by many, although a large variety of input methods have been proposed since the first mobile phones. 12-button phones with predictive text-entry methods (e.g. [1]) have mostly been replaced by touchscreen devices with soft-keyboards. These devices however suffer from the “fat finger problem”, i.e. the fact that a human finger is thicker than a typical key on the virtual keyboard [2] and thus methods for automatic prediction and correction were added, e.g. in the form of gesture-based systems for keyboard entry, e.g. SHARK [3], ShapeWriter [4], and SwiftKey [5]. One of the alternative means of text entry is handwriting, which works naturally with GyroPen input.