Blender addon master Samuel Bernou is on fire, releasing yet another free Blender addon in the span of a month, "Surface Rig".
— Samuel Bernou (@pullusb) June 28, 2021
This latest add-on facilitates the placement of armature bones on object surfaces and can work on both regular and Grease Pencil objects. While the addon can help with the quick sketching of armatures on mesh surfaces, it is especially useful for the Grease Pencil use case, as there are currently no built-in tools to snap bones on the GP canvas.
Samuel, known for his Grease Pencil centric add-ons such as the now-bundled-with Blender Grease Pencil Tools addon, had also recently released the Onion Peel addon available on his Gumroad.