WheresMySound 1.0.1 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 Mac app is a product of Marco Barisione. WheresMySound for Mac lies within System Tools, more precisely Device Assistants. 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.
From the developer:
Where’s My Sound is a free macOS application showing the device that plays the sound on your Mac. The program adds an icon in the menu bar of your macOS desktop showing what kind of device is currently selected for playing the audio. Therefore, you can see at a glance the active audio output.
You may want to check out more Mac applications, such as Missing Sync for Palm Pre, PSPWare or FourEyes3D, which might be related to WheresMySound.