Currency shows you all of your currencies with just a mouse-over. It only shows currencies you have some of, and there is no configuration needed but there are options in the interface addon panel if you choose to. The position of the Minimap button may be changed by left-clicking and dragging it to your desired position.

This is accessed via the slash command /currency or by right-clicking on the Minimap icon or by use of the in-game interface addon panel.