(from NALA Case Study)
This site allows you to create graphs that...
Solve equations, graph functions, create constructions, analyze data, explore 3D math!
You can use the website or apps for iOS and Android devices.
The Resources section is where teachers post interactive graphs they have made.
There is a list of GeoGebra websites that will help you incorporate this way of doing math into your curriculum here: www.haveyougotmathseyes.com/geogebra-websites/