University of Washington has a project with the awesome name dollar family of gesture recognizers.
They have demonstrations to go with their recognizers, but:
recognizers they provide (e.g you cannot $1 and $P recognizers because the definition of
Pointclass is different in both).
- the demos do not work on touch devices D:
I was amazed by how quickly it learns and well it is able to generalize from even a single example to categorizing cursive handwriting which barely looked like the original templates.