I dont know what the poster is using, but I just looked for something similar for my Android Phone. I found an app called SoundID that does what they describe, i.e. a hearing test for you and your headphones including an audio preference test. It then did some eq’ing, and that did have a pretty good effect for me. I use the cheapest chinese earbuds off of Temu, but it still did improve the audio for me. Link to the play store: https://play.google.com/store/apps/details?id=com.sonarworks.soundid.mobile

The white version seems to be in stock, only the black one shows up as shipping later. There is a comment elsewhere in this post stating that they got one already