GeoGebra

Screenshot for GeoGebra

GeoGebra is a handy, interactive application designed for students, primary to the collegiate level. Users can engage and blend geometry, algebra, spreadsheets, graphing, statistics, and calculus. GeoGebra offers an authoring tool to create interactive learning materials/lessons in the format of a webpage as well as many downloadable free resources. Also, it has apps for iOS and Android devices. For all grade levels. 

Comments should appear here if you have Javascript enabled.