Rip Vertices and Extend
Mode
Edit Mode
Vertex ‣ Rip Vertices and Extend
Hotkey
This tool takes any number of selected vertices and duplicate-drags them along the closest edge to the mouse, When extending an edge loop, it extends the vertices at the endpoints of the loop. The behavior is similar to the Extrude tool, but it creates an n-gon.
It helps to easily add details to existing edges.