This addon allows you select back side of a mesh without enabling X-Ray or Wireframe mode. So, you don’t have to press Alt+Z or switch the modes every time you want to include rear geometry(points, edges, faces) into your selection. And this saves a lot of time and clicks! It works very similar to Modo style selection: left mouse button (LMB) - selects front geometry, RMB - selects front+rear geometry. You can assign MMB instead of RMB also.
There are two modes: Rectangle Selection and Lasso. You can switch between them by clicking the icon at the screen or assign a shortcut.
After installation you have to adjust some settings for your right mouse button(RMB).
You’ll see the following area inside of the addon:
For 2.8, 2.9 https://gumroad.com/l/xFzti
* Added the ability to change the position of the icon
* Fixed issue with saving hotkeys after restart
* Installation is greatly improved. It is much easier to install the addon now
* Fixed the issue with loading config if Blender was closed when BO was installed selection mode
* Fixed the issue with re-configuration hotkeys after restart
* Now the addon consists of 1 file instead of 3
* Added the ability to set and change hotkeys inside of the addon properties
Thanks to @Antony for translation and instruction.