The Easiest way is by using Monaca. https://monaca.io/ You just build the app in Monaca, and Monaca will let you export the app in Android/iOS etc. Used this in my last place of work without any issues. Source: over 1 year ago

Apple won't except a pwa, but it's quite easy to turn a pwa into an app. Check out https://monaca.io/ it's a club based build platform. Basic upload you pwa to a blank Cordova project and hit build. Source: almost 3 years ago

Hi! I've been turning my Twine game into an APK for Android using https://monaca.io/ it also apparently will convert it to iOS, Mac, Windows & Linux - but Android is all I've tried right now. Source: over 3 years ago

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