Ever played Black and White? If so, you must remember the innovative spell system, which required you to trace a spell's symbol to cast it. My gesture system allows just that. With just a few lines of code, you can add shape recognition to your games. It will take you no more than a few minutes to master the system. The help file also has an easy to follow step-by-step tutorial that will guide you through the process of recognizing a shape.
Technical Details - License

What's new in Version 5.2:
Added a ton of functions
Made the recognition for pointy shapes much better

News:

The source is out, and included in the download from GMBase. 

Added some info in the update section about the next version.

Over 800 downloads! (600 on new host, 200 on old)

Featured in Markup Magazine!

The download includes the gesture extension (.gex), the demo (.gmk registered), the help file, and the source.

Planned Updates for Version 6:

I might get around to a version 6, but I'm busy with school and other things.  The version I was working on is far too unstable to release, and the source is ugly.

Download (Credit Required):

GMC Link

Old Version 5.1

Old Version 4.4