Google Docs and Evernote have an "Add to Home screen" feature in the More menu for docs/notes. When selected, it creates an icon on the device home screen (with editable title) that when clicked, opens the app and the specific note/doc with one click. It's immensely useful for frequently referenced notes/docs and I've been using it for years.
Use Case: I'm a songwriter and I keep a running list of song and lyric ideas, which can strike at any moment. With this feature I wouldn't have to open Amplenote and then find the Song Ideas note. I would just click on the Home screen icon and the Song Ideas note in AN would open allowing me to start typing immediately.