StartupChimeMute 2.1.7 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 application lies within System Tools, more precisely System Optimization.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. This Mac application is an intellectual property of AtalantiaDevelopment.
From the developer:
StartupChimeMute mutes the startup chime on OS X. The process can also be undone with the included deinstaller. The application is not required to run after installation.
You may want to check out more software for Mac, such as Spanning Tools for Mac, Snow Checker or SBSystemPrefs, which might be similar to StartupChimeMute.