Blue Cat's StereoScope Pro is a real time stereo field analyzer with multiple views and MIDI/automation output capabilities. It is a powerful help to analyze how the audio signal is spread in the stereo field, and you can easily detect potential phase and mono compatibilities issues.
The stereo analysis can be controlled in details, and the precise measurements capabilities combined with the zoomable displays let you monitor what is exactly happening.
Choose your preferred view for your needs: real time stereo field display, evolution of the stereo image over time (2D or 3D) or output parameters that explicitly describe the average position and extent of the audio signal in the stereo field. The 3D waterfall view lets you see in details from your preferred viewpoint the evolution of the stereo image over time.