Unless I’m blind there is no way to quote a user in mobile view. This bothers me since one of the badges is to quote a user.
At least on iOS, you can select the text in the post you want to quote, then tap the little quote popup box that appears just above the selected text. That will open a reply window with the selected text quoted.
Pretty sure Android works the same way, though I’ve not tested it myself.
When I highlighted your text that’s when the quote button popped up, that’s a little weird and hidden haha. Thank you!
You can also use BB Code. Type [ quote=username]the quote[ /quote]. No spaces.