The Nugen Audio AB Assist plugin is a brilliant free plugin to help you compare two different plug-in or two completely different process chains.
AB Assist plugin was only available in AAX format for Pro Tools users and you used to have to get it through the Avid Store, but not anymore.
Now Available In AU & VST Formats Too
Exclusive To Production Expert
You can only get it through the Production Expert family of sites, Pro Tools Expert, Logic Pro Expert, Ableton Live Expert, Reason Expert and Studio One Expert. You cannot get it anywhere else.