The 1.6 version of REXPlayer 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 software is included in Audio & Video Tools. We recommend checking the downloaded files with any free antivirus. This Mac app is an intellectual property of MethodRed Technology LLC.
From the developer:
REXPlayer is a handy Rex file and slice sample player for the Mac. You can use REXPlayer anytime you need to listen to Rex files quickly. In addition, you can use it alongside your favorite Digital Audio Workstation (DAW) as a great way to audition files and slices before importing them into your project.
You may want to check out more software for Mac, such as Easy REX Player, which might be related to REXPlayer.