uCON64 2.0 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 Games, more precisely Tools. 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:
uCON64 is a port of an open source command line tool with many options for backing up, restoring, handling, managing, splitting, joining, converting and patching ROMs and more. Supports a large number of video game consoles and handhelds.
You may want to check out more software for Mac, such as World of Warcraft Interface AddOn Kit or Virtual Combat Cards, which might be related to uCON64.