Unfortunately, there doesn't appear to be a free camera gesture SDK available. The few companies I've found require you to contact the company for the SDK.
Licensing
Please contact us for details: nanogest@nanocritical.com.
Academic research license
If you are a researcher or a student in an academic institution, we can give you access to the Nanogest SDK under a non-commercial research license, at no cost. Please contact us for details: nanogest@nanocritical.com.
via http://www.nanocritical.com/nanogest/
Other possible solutions: