Overkill 1.0 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X was originally produced by Felix Krause. 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. The software lies within System Tools, more precisely System Optimization.
From the developer:
Overkill is a simple, elegant Mac app, that runs in the background and makes sure iTunes never interrupts your work. However, for those movie nights where you actually want to use iTunes, you can just click on Pause Overkill and enjoy the evening. If you have other apps you don’t want to launch automatically (e.g. Photos app), you can add those apps to the Overkill list as well.
You may want to check out more Mac applications, such as Shave Video, TimePreserver or StatKeeper, which might be related to Overkill.