Thx for your feedback, glad you like it. The demo suite source code is pretty ugly, so I'd rather not publish that one, I think it would confuse ppl more than anything. I could probably fix it though, if you really want me to.
For now, I've added another code-field to my first post titled "usage", which should allow you to make use of the features the class has. Plus, pretty much all the code in that class is commented, so that should help too. Usage is fairly straigthforward, you add the trail just like any other FlxGroup. (You need at least two parameters, sprite to follow and image to use, though)