When you hover over a menu item, a submenu appears. But apart from hovering over an item, you can also simply click on it to follow the link. Now, what should happen when you tap on the item with a touch device? Should the submenus appear, or should the link activate? Or both? Or should something else happen? On iOS, something else happens. The first time you tap a link like that, the submenu appears; in other words, the hover event fires. You have to tap a second time to actually follow the link. This is confusing, and not many people will tap a second time. On Android, the submenu appears and the link is followed simultaneously. I don’t have to explain to you that this is confusing.