Melda MOscilloscope

MOscilloscope is a powerful oscilloscope equipped with a pitch detector:
simply – wow! This thing delivers that WOW factor right out of the box.With most oscilloscopes, you’d have to do some manual work first in order to zoom onto the desired section of the waveform. But MOscilloscope does all the hard work for you, thanks to its built-in pitch detector which locks on to a single cycle of the waveform like a boss. 
n addition, MOscilloscope packs all of the great features found in MeldaProduction plugins, such as a fully customizable and resizable user interface, precise input monitoring, GPU acceleration, and so on. They’ve really improved the visual style of their plugins with the last few updates, making them compatible with absolutely any screen size and workflow you can think off.

https://www.meldaproduction.com/plugins/product.php?id=MOscilloscope