Interested in loudness?
But how loud is too loud? What about your true peak? Headroom?
To measure your loudness I can recommend Youlean Loudness Meter.
It's a meter plugin where you can see how loud your song is (perceived loudness in dB) in combo with your True Peak Max.(don t want your final mix to clip or be squashed)
Loudness and True Peak is handy for your mix, As each streaming service has its “correct” loudness levels. (you can check the optimal levels here: https://www.masteringthemix.com/blogs/learn/76296773-mastering-audio-for-soundcloud-itunes-spotify-and-youtube)
There are presets for these different online streaming service but also for film,tv and gaming.
The Pro version also measures your audio dynamics.
It's a clear plugin and nice to use.
There is a free version and a Pro version to buy.
Check out the video below for more info. In case of questions, just drop a comment