The only thing I know with half of those features that's discontinued is the old Darkroom app but that doesn't tackle some of the bigger compatibilities. Source: about 2 years ago

Not sure if this is applicable, but if you're using Word or Scrivener or something, you may want to switch to a plaintext editor like Dark Room or Typora--something that won't underline your spelling and grammar mistakes. It doesn't even have italics or bold to get in your way. Dark Room is a little old, but I found it here: https://codex.jjafuller.com/books/dark-room/page/overview. Source: over 2 years ago

I use DarkRoom. Full screen, no distractions, no "fancy" auto-formatting. Source: about 3 years ago

Https://ommwriter.com/ Is wonderfully serene and distraction-free. Source: about 2 years ago

Congratulations on making the app! Have you heard of Omm Writer? If you're familiar with it, could you tell me some of the differences between it and Frost? (Asking because you described your app as "first of its kind," and I'm trying to understand what you mean by that.). Source: over 2 years ago

I use software called OmmWriter that is completely clutter free and super simplistic and just allows me to write uninterrupted and without distractions. Highly recommend! Source: over 2 years ago