This mod is for displaying the count of items for users who can't or don't want to use /use (item) or #show (item) macros to accomplish the same thing.
To be clear, if you want to display how many Ragveil you have as you're flying around Zangarmarsh, make this macro:
choose the red ? macro icon. The macro's icon will display how many Ragveils you have.
This is standard behavior of the default action bars. Almost all bar mods should be able to handle this. You do not need this mod or any mod to do this if your action bars behave.
If your bar mod doesn't, or you want extra buttons on the screen, you can use this mod. It's not super fancy because it was initially typed up on the forums.
The bar is turned off by default. You can turn it on via a key binding or /watch on (further slash commands at the bottom)
While the bar is on screen and visible (unlock to see all slots), you can drop items into slots. You can drag items off the slots or move them to others like a normal action bar. While the bar is off, it doesn't process any events.
There are some slash commands to customize it:
/watch on|off : turn window on/off
/watch (number) : change number of buttons on bar
/watch lock|unlock : lock/unlock the window
/watch scale (number) : set scale
/watch rotate : flip vertical or horizontal
/watch reset : reposition bar to center