Available for download, PSPAudioWare PSP TripleMeter is a plug-in that provides metering options for the mixing process. It allows you to meter in VU (volume units), RMS (average), and PPM (peak). Use this plug-in on tracks, submixes, buses, and the master bus.
You'll be able to calibrate the meter's reference levels and hold times. You can monitor in mono, left, and M/S modes. Configure each instance of the meter to work in session mode (i.e., linked throughout various tracks of your mix), or individually.
Each meter also has processing options that allow you to adjust gain and high-/low-pass filtering on each plug-in. You can also add label strips to remind yourself about different facets of your mix.
This software is compatible with Mac and Windows platforms. It will operate in AU, VST, AAX, and RTAS formats.