Google seems to be worst with this. In addition to having confusing icons, they're not even consistent with themselves. The Gmail archive icon on my Android phone is a picture of a filing cabinet. The archive icon on their main web app is a box with an arrow pointing down. They're two completely different icons for the exact same action.
They balance that by elsewhere using the same icon for completely different actions, like the sealed envelope that means Compose as well as Mark Unread.
