InstantVariable is a scripted tool for Indesign CS6-CC. It belongs to the class of what we now call “responsive scripts”, those that automatically react to a particular user gesture. Run the script once to activate the listener, then it will interact with you whenever a custom text variable is selected. Rerun the script to stop the listener. It's that simple:

InstantVariable is intended to run in InDesign CS6 and CC.
How to install the script in InDesign.
• This script can be installed in a “startup scripts” folder (in case you want to make it active by default.)

Bugs and feedback?
Please, let me know what you think about this script via Twitter.