StereoTool
There's a free stereo utility plugin by Flux called StereoTool v3; you should grab it.
You put it at the end of your master bus, after the limiter. (Metering plugins should always go after the limiter, so they take the effect of the limiter into account.) You can also use it on individual stereo tracks, to see what they’re doing.
StereoTool has an excelle…