Ok this one isn’t really a surprise.. Combining a spectrum analyzer, a correlation meter, a level meter and more, SPAN is probably the most recommended free plugin out there, and a must have for any music producer or musician !

Whether it be for sound design or mixing, an oscilloscope is a very useful monitoring tool: From observing how a compressor shape transients to checking low frequencies phases interactions, this freeware will get you covered.

Managing your sample pool can be tedious: This free plugin aims to help you in this task by providing an all-in-one solution for organizing, searching and browsing the indexed sample content.

Keep an eye on the time spent on your project with ProjectTime: It runs as long as your project is loaded, can be paused when needed and can generate a commented log.

This neat little plugin guesses chord names based on MIDI input or clicked notes: Although the developer seems inactive, luckily this plugin is open source and can still be found out there.

Both developed by MAAT, 2BusControl is a universal L/R or Mono/Diff monitor control that also features a correlation meter, while GON is a free goniometer that replicates an analog oscilloscope with a simple and straightforward visual interface.

If you mix with headphones and ever wondered how you mix will sound in a different environment like your car, a recording studio, a big venue or a 5.1 surround speaker system, just throw this plugin on your master and check it out !

Ginger Audio’s Virtual Audio Driver isn’t a plugin, but more a utility tool that can pass any audio signal to other applications without any latency: Useful for streamers, engineers, podcasters, educators
Unfortunately it’s currently available for Mac only…