I've often wished I could add a comment to a running diagram while debugging. Either a note for later to correct something or some commenting as I watch it unfold.
Here's a workaround based on a right-click plugin. The idea is that you can create notes on certain portions of code while it's running. These will be aggregated and you can then have it create associated free labels after the VI is done executing.
1. Right-click on the object to mark and select "New Debug Note..."
2. Write a note about the object you clicked on
3. A list is maintained in the debugger notepad
From this list it is possible to quickly return to the marked object by clicking on Show Object. The Label Object and Label All buttons are only enabled if the VI is not in run-mode since it doesn't work otherwise.
This window stays open until you close it by pressing on Close. Closing the window will clear all notes but will open again if you create new notes.
This window allows you to easily navigate back to the code portions you marked at run-time and to quickly create free labels:
Label placement is random in a circle around the object and is placed on the top-level diagram (hence the black frame). This could be improved to look for free space, preferably inside the same diagram as the object it points to. Not really interested in that at the moment so I'm unlikely to attempt that.
edit 12.12.2016: removed compiled code.
Attachement is saved in LabVIEW 2015. For install instructions, go here.