Video tutorial: for Blender 2.8x or Blender 2.79

Installing the addon:

• Unzip the downloaded file, and place the .py file somewhere on your hard drive
• In Blender, press Ctrl-Alt-U > Add-ons > Install from file >...
• Look for the .py file ("skin_selection_[version].py") then click Install from File
• Check the box next to the addon in the list to enable it.
• Click Save User Settings at the bottom left of the window.

1)Create the vertex groups:

-Under the Vertex Groups Creation label, add up to three bone controllers.

-Click Create VGroup. A corresponding vertex group is added. The group are easily recognizable with the "fs:" prefix for "face selection" vertex groups.

-Assign the faces/vertices for this vertex group.

-Optionally if the group is from the right or left side, click Mirror Selected VGroup to mirror it on the other side.

2)Display options:

Optionally change the display parameter: color, alpha...

3)Click Start! 

-Only the meshes will be displayed.

4)Click an area on the mesh to select the associated controller. 

Click to select the first mapped controller, hold Shift for the second, and Alt for the third.

5)Press escape key or the Stop button to go back to the normal mode.

Notes:

• The selection will be wrong in ortho mode, switch to perspective mode! (numpad key 5)
• Multiple bones selection is not yet implemented.
• Does not work yet with subsurf modifier in OpenSubdiv mode.
• Bones controllers names must end with a two characters side, eg: "hand.l" or "hand_L" for left, "hand.r" or hand_R" for right side. This allows skin selection to work with mirror modifiers.
• If multiple bones are included in the group, they must be from the same side.
• When switching to edit mode, the skin selection will stop.