Mjolnir 0.4.3 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.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This free Mac application is a product of Steven Degutis. The program lies within Productivity Tools, more precisely Office Tools.
From the developer:
Mjolnir is a lightweight automation and productivity power-tool for OS X. This app lets you automate common tasks using the language Lua. At its core, it doesn't actually do anything besides load up a Lua environment; the real power lies in all the useful modules that you can install.
You may want to check out more Mac applications, such as Yay! Zombies, which might be related to Mjolnir.