I was considering trying Flashmode, an instant-preview add-on for TeXshop:
See also one of the answers here: Is there any way to get real-time compilation for LaTeX?
However, it seems the Flashmode download page was last updated in 2013:
I'm using the current version of MacTeX (2018), which contains the latest version of TeXShop (4.22), on a Mac running MacOS 10.13.6. How well does Flashmode work with this more current software? And about how much delay should I expect to see in the updating of the viewer if I'm using a mid-2014 MacBook Pro with the fastest processor option?
I ask because I'm currently evaluating BaKoMa TeX Word, and was wondering if there are any other options I should consider.