I've been using nvim in termux on foldable phone since I've bought phone in that form factor. It works great, I'm using "unexpected keyboard" as input method for faster special symbols access. It works pretty well. Good enough for me to program on the go.
Thanks for letting me know about the Unexpected Keyboard app. It'll take some getting used to, but having arrow keys and punctuation available without changing modes is pretty awesome.
I can even hit Ctrl-A to select all, Ctrl-C to copy, etc. This alone will help text editing on my phone.
Seems to be quite an improvement. Thank you for the tip!
But it would be even better if it had "stylus mode" because, with a precision stylus, it's easier to tap directly alternate characters than to drag from the center of the button toward the needed variant.