The 2.0 version of CocoaRTLServer for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application belongs to System Tools. 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 free Mac application is a product of Black Cat Systems.
From the developer:
Cocoa RTL Server makes a RTL SDR dongle appear as a networked SDR, following the RF Space protocol. It works with SDR apps such as SdrDx. It also acts like rtl_tcp, so it can be used with Cocoa1090 and similar apps. This app requires an RTL based TV tuner with an E4000 or R820 tuner.
You may want to check out more Mac applications, such as ToFi, iStar Composer or Portable Nvu, which might be related to CocoaRTLServer.