Having metering and audio analysis plugins is all well and good, but if you can't make sense of the information that they're giving you, they're not going to be much help.
Mastering The Mix's Levels is designed to be different, telling you which specific aspects of your mix need attention so you can get to work on fixing them.
The plugin focuses on four issues: Headroom, Stereo Field, Dynamic Range and Bass Space. Switch between these and the interface adapts accordingly; you're given instant feedback on how your mix is faring in each of these areas.
Levels was developed by 28 Palms and its visuals are designed to be simple and easy to understand. The theory is that, by quickly diagnosing what's wrong with your mix, it'll save you time and help you to get a better result.
Find out more on the Mastering The Mix website, where a fully-functional 15-day trial version can be downloaded. Levels is available for PC and Mac in VST/AU.AAX formats and costs £69.