Hi,
This is a work in progress animation arc tracking addon i wrote for Blender 2.79. it has a little on drawing to the viewport using bgl and a beginning example of a modal operator. Please modify use at your own risk.
There are still quite a few things left to make it better - like being able to get the number of frames we wish to see as a parameter that can be passed to the tool. now its just fixed at 10 frames back. Also it currently only supporting pose bones of an Armature. It would be nice to extend to meshes etc.
To install each of the 3 script files need to be copied into a folder with a name and that folder needs to be in Blender's addon script path. To launch modal addon can use spacebar and select the addon - to exit can click the esc key.
Happy Scripting!
