PWA. I have the “Discourse Tab Bar” plugin installed for mobile and he says there was a back arrow right above that, on the left side of the screen.
He said it was on all of the themes, it was a “purple back button” (color might be related to the theme, if it would be affected by that because I have one with a purple theming) and you could press it to go back pages. I have nothing IOS and I’ve never seen anything related, and he’s on IOS, so I would guess it has to be an IOS thing?
I found this https://invisioncommunity.com/forums/topic/466628-add-back-button-for-pwa-on-ios/ referencing an IOS back button on the PWA and shows something with a back and forward set up from this site
I have no idea if this is what he’s talking about, he talks…in a special way which makes it difficult to get any amount of detailed information without 15 back and forths