MathDisk became an advertiser on Free Technology for Teachers. Even if they were not advertising here I'd still think that MathDisk is a neat service.
MathDisk is a service that teachers can use to develop interactive mathematics worksheets. Through MathDisk's "Math Builder" tool you can design mathematics models that your students can use online. The models and worksheets you develop online can also be downloaded to use offline if you also install the MiBook software on your desktop or on your Android device.
If you don't have time to create new materials, the MathDisk gallery has pages of models and worksheets that you can choose from. Everything in the gallery, like everything you create through MathDisk, can be downloaded and or embedded into your own website or blog.
The video below offers an overview of the MathDisk's features.
MathDisk offers an extensive playlist of tutorial videos for new users. That playlist is embedded below.