Do you mean the add-on that had balls for the settings sliders along the 3d motion path?
Its not really needed. If you have a pose library open in the side pane of the 3d window you can click drag on the pose icon to adjust its effect. That is basically the same as what that old addon did.
Yes - it was one of the best add-ons ever. That functionality should be built in. The way it allowed animation tweaking in full screen was fantastic.
Hey - just found this…
Someone is trying to keep it alive.