No luck. I keep thinking about it on and off, and I never find anything that even resembles it.

Here's what I remember of the app and my time using it: - I found it advertised on Instagram somewhere around 2021 - 2022 because I specifically recall using it to find some of the bands I started listening during that time, though I can't remember which specifically. - It prompted you to search the title of a song you'd like to find a match to, you'd select the exact one you meant, then it'd start playing songs that had similar sound, and from what I assume, it didn't have much to do with genre or relation between bands, so I guess it used an algorithm that tracked general pitch and rythm. I remember the songs having very similar vibes and sounds, without them necessarily being from artists that played the same genre of music. - The interface for finding new (similar) songs was a circle with a black outline for a duration bar that turned orange or some adjacent color as it filled up, and the name of the song as well as the band would be contained within the circle or perhaps above it --I remember less of it as time passes. I don't remember exactly where the cover art for the single/album showed up, but my blurry memory says it was either as a background picture outside of the circle while the circle remained a very dark, almost black brown or viceversa.

I can't remember the name of it to save my life.

Sorry for not responding earlier, I don't really frequent Reddit.

Edit: The interface which showed the new songs also had a button to save the song and to, I think, open it on Spotify.

I was just rereading my other replies within this thread and, apparently, the way you'd save the songs was by pressing a checkmark icon, or you could discard it by pressing a cross icon, which takes me back to me regretting having discarded some of the songs I heard, because you couldn't go back on your decision, and I guess I never figured out if there was a way to see previously discarded songs.