Using keyboard shortcuts on Android phone without a physical keyboard:
Install Hacker’s Keyboard
In Settings enable Use permanent notification
Normally a keyboard only activates in an input area, but now one can just click the permanent “Show Hacker’s Keyboard” notification - and use all the useful shortcuts including Hotkeys.
In Settings you can also enable “Gesture and Key actions” to use left/right swipe OR volume up/down to change keyboard size quickly.
Picture of “Show Hacker’s Keyboard” in my notifications dropdown.
[“Hacker’s Keyboard” has to be the active keyboard for the “Show Hacker’s Keyboard” to work.]
I’ve implemented Fold all headings and lists as ALT+Left Arrow
Picture shows ALT key pressed
Picture shows everything folded after ALT+Left Arrow pressed
PS: How to Use Hacker’s Keyboard
… and here are some cool outlining keyboard shortcuts …