SketchUp is a fun tool that supports student creativity. Math can be a component of a SketchUp activity but it is not necessary. This link is to the video tutorials.
The Scratch Programming language provides an excellent introduction to computer programming. The most common use of the language by middle school students is to develop computer games. Grade 5 - 8 teachers use Scratch to augment math concepts. The program is free but you need to register to download it. Once registered, you can view many sample programs that can help with programming concepts.
Create Android Apps for phones and tablets.
Great source for math and science activities.