Select several neighbouring verts/edges with at least one "border corner"(3
Invoke addon (its in the Mesh Tools panel).
If you wish to hotkey Quadder:
In the Input section of User Preferences at the bottom of the 3D View >
Mesh section click 'Add New' button.
In the Operator Identifier box put 'mesh.quadder'.
Assign a hotkey.
Save as Default (Optional).