MACHIN3tools is a free, continuously evolving collection of blender tools and pie menus in a single customizable package.
in Blender 2.83 - 2.92, from the zip file or manually, in the file browser great when updating, as it keeps all previous addon preferences.
see MESHmachine installation for reference, it's the same process for any addon.
Most of these tools are accessed via keymaps, that can be adjusted in the addon preferences. Others are accessed via the object or edit mode context menus.
Smart Drive and Unity Export are accessed from the 3D View's sidepanel, while Cursor Spin is found in the Extrude menu.
Mirror and Un-Mirror
Edge Constraint Deus Ex
Pie menus in MACHIN3tools, typically provide a whole set of new custom tools themselves, they are not just a re-arrangement of native Blender tools.
These tools are not mentioned above, but there are dozens of them. The Cursor and Origin pie is a great example, but it's similar for most other menus.
Cursor and Origin Pie