Felix CAT is not available for Mac but there are some alternatives that runs on macOS with similar functionality. The best Mac alternative is Poedit, which is free. If that doesn't suit you, our users have ranked more than 10 alternatives to Felix CAT and five of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to Felix CAT are OmegaT (Free, Open Source), LF Aligner (Free, Open Source), BabelEdit (Paid) and Text United (Paid).
Poedit is cross-platform gettext catalogs (.po files) editor. It is built with wxWidgets toolkit and can run on any platform supported by it (although it was only tested on Unix with GTK+ and Windows).
LF Aligner helps translators create translation memories from texts and their translations. It relies on Hunalign for automatic sentence pairing. Input: txt, doc, docx, rtf, pdf, html. Output: tab delimited txt, TMX and xls. With web features.