Tools Pie
shortcut Q
The Tools Pie has only one purpose: allow using some addon-supplied tools, while keeping the 3D View's toolbar collapsed and out of the way.
These addons are HardOps, BoxCutter and HyperCursor.unreleased
Other than these, I prefer not using tools at all, and use the Select Box tool as the default, which the pie also supports switching to.
the tools pie with the select tool enabled and HardOps, BoxCutter and HyperCursor registered
the tools pie with the select tool disabled and HardOps, BoxCutter and HyperCursor registered