Primary support is via the Unity3D forums:
http://forum.unity3d.com/threads/wip-snap-and-plug-join-anything-to-anything.268490/
Alternatively, you can get me on twitter (may be quicker, but I can’t give a detailed response!)
You can also email me directly — but please note: I receive a lot of email every day, and if you email me directly I might miss it. The Unity forum is generally a better place for support:
support @ snapandplug.com