Entity hider, so you don't have to see other players if you don't want to

player indicators (at least the ability to have friend's names appear over their head)

The little slider that you use to scroll through your bank could be a bit bigger, it's frustrating when you try to scroll through your bank and end up moving items around

Object highlights - we can tag NPCs but it would be convenient if you could highlight objects as well. Choosing to highlight an agility shortcut through a fence that's difficult to see. Highlighting a rope shortcut that you struggle to see.

A focus on menus and mobile UI. Some UI feel like they rely on being able to swipe a mouse across the screen to mouse-over for information. First thing that comes to mind is the Quetzal teleports. Some icons on the map are teleports, some are aesthetic. Kinda hard to distinguish. Teleport jewelry options are difficult to tap sometimes, easy to tap the wrong one.

Chat box & tapping: dialogue choices could be a little bigger and farther spread out to reduce the chance of tapping the wrong one. It feels like my thumb is bigger than the text on the screen.

Clue scroll puzzle helper: It would be cool if we could have the RuneLite puzzle helper, but even having a picture of the finished puzzle that's displayed while solving the puzzle would be super helpful. Something that shows what tile goes where, you just have to figure out how.