I scanned this topic, but couldn't see anyone mention DEVONthink? Also, Highlights is coming to iOS soon. It has been in Beta for some time, but my understanding is it will be released soon. Also, f...

Anoter option is the excellent cross platform Notebooks app: https://www.notebooksapp.com

I have covered Notebooks a bit at https://appademic.tech (mainly on iOS). Alfons is one of the more approachable and responisive developers I have come across, if you're commited to using Notebooks an...