Is there a content aware fill plugin for Gimp on mac

WHAT YOU SEEK
I see you know you found Resynthesizer already.
Yes Dr Paul Harrison wrote Fixer in 2000 which grew into Resynthesizer in 2003 as part of his PhD at Monash University.
His GIMP plug-in provides a menu item "Heal Selection". Adobe released its similar functionality in CS5 in early 2010! 7yrs later.
The technical name for what this process is "exemplar-based texture synthesis".

WHERE TO GET IT
The plugin registry is great to find out about what's available but you should search more widely to find the most up to date binary files for your specific platform. Maybe it is best you get a modern copy of GIMP for OS X and try out Resynthesizer yourself.

Visit http://gimp.lisanet.de/Website/Download.html
Which Mac OS version: e.g. 64-bit Mountain Lion ( aka OS X 10.8 )
Download GIMP : e.g. native version 2.8.6 from "Lisanet.de"
(old style MacPorts version still could work but this version uses OS X Quartz UI)

Simone Karin Lehmann included many plugins already with the above package: "Wavelet Denoise", "G'MIC", "Liquid Rescale", "Lens-alike focus: Focus-Blur", "UFRaw" including lensfun, "Resynthesizer" , "Wavelet Decompose" , "Fix-CA" for chromatic aberration , "wavelet sharpen" ...

HOW TO USE IT
See http://blog.patdavid.net/2012/08/getting-around-in-gimp-heal-selection.html.

PS. If your copy of the G'MIC plugin is recent it will list a filter under Enhancement / Inpaint [patch-based] .. see here for info & examples http://gimpchat.com/viewtopic.php?f=28&t=6693&start=10