sketchometry is an interactive construction and exploration tool for plane Euclidean geometry. Points, circles and lines can be sketched on the screen with fingers or stylus. sketchometry identifies these gestures and generates an exact figure. These constructions can be explored in a very natural way by dragging, rotating and manipulating the geometric objects. The constructions are saved locally or in the cloud. Embedding in interactive eBooks or HTML export is also possible. sketchometry is free to use and is developed at the Center for Mobile Learning with Digital Technology of the Bayreuth University, D-95440 Bayreuth, Germany.