See the Blender artists forum post for more info: https://blenderartists.org/t/updated-version-of-the-old-motion-trail-addon/1395865 (Also includes further usage instructions)
Expect changes frequently, or rarely.
To get the addon, go to the src folder, click on the only python file there, click on raw, and save that.
After installed, the addon is under the "Testing" tab.
This is an update of the old motion trail addon by Bart Crouch.