Hammerspoon 1.1.1 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within System Tools, more precisely System Optimization. This free software for Mac OS X was originally created by Hammerspoon.
From the developer:
Hammerspoon is a desktop automation tool for OS X. It bridges various system level APIs into a Lua scripting engine, allowing you to add powerful effects to your system by writing Lua scripts.What gives Hammerspoon its power is a set of extensions that expose specific pieces of system functionality to the user.
You may want to check out more software for Mac, such as WinShortcutter, Mac Pilot or AppTrap, which might be similar to Hammerspoon.