Quoting the main README,

Mac OS X

Currently no support is given for iOS. If anyone is interested in getting this to work feel free to contact me.

Apple's iOS is their phone and tablet touchscreen operating system. I assuming that was a typo?

Apple have since rebranded Mac OS X as macOS, their desktop and laptop operating system.

I expect your tool to work there much like it works on Linux, providing the dependencies can be installed - but pygments and Gtk look like the first hurdles, cross reference conda-forge/pygobject-feedstock#20