App is stats.fm, it works free, but requires premium for some features. Pretty sure there still is a lifetime option, which is a pretty good deal if you like music and want more recaps than what Spotify Wrapped provides.
When I reached the end of the right side, it kept alternating left and right, until there was no more space on the page.
I'm pretty sure you can't change your username, only display name. And this account is both. Literally two of the songs. Even the two of my favorite songs on the album. That is wild. And even the two songs coming after each other, in the same order. It doesn't seem legit, but I can't see any other possibility, any enlighteners in the comment?