It is a common gesture in iOS to tap the status bar (bar at the top of the screen) to scroll to the top of the page.

Apollo improved on that so if you accidentally tapped and jumped to the top, you could tap it again and it would return you to where you were on the page. This was also useful if you were in the comments and wanted to quickly check the OP then jump back to where you were in the comments.

It’s a great feature and would be wonderful if wefwef decide to implement it!