A full version app for Android, by devdnua.

Equalizer Pie is an audio equalizer that lets you adjust the sound balance and frequency with 14 audio bands.

It works with many audio players, even the ones that don’t let you adjust the sound balance or frequency, such as YouTube Music and Google Play Music.

Equalizer Pie lets you easily adjust the sound balance between channels (right/left) to create the most immersive audio experience.

Use preamp and lower level for Bluetooth headphones as it makes other noises when any of frequency band summary level (preamp + level of band) is more than 0.