MultiApp VS AmbientMusicMod

There is that on Github.

There is this app that allows you to install parallel apps, it works by running the app in a virtualized container https://github.com/WaxMoon/MultiApp

Multi App - run multiple instances of same app

many 3rd party reddit clients have a simple account switch feature built in - i use dawn, but infinity, etc have the feature as well - another option is app-cloning (1+, etc built it into their android, but apps like insular and MultiApp can add the feature if your phone dosnt ship with it)

Multi App: launch multiple same apps at the same time, Run 2 accounts/multi accounts

Ambient Music Mod - its Foss and shows the song playing nearby directly on your lockscreen just like pixel devices.... But doesn't have that much of a big database as shazam

Yes, 100% sure. Someone reverse engineer it for other phones https://github.com/KieronQuinn/AmbientMusicMod

Ambient Music Mod (version 221): Port of Now Playing from Pixels to other Android devices

You can try out the Ambient Music Mod, an app that brings the Pixel feature to any phone you can install the app in. I think it's open source, but not sure if you'd need to root the phone. https://github.com/KieronQuinn/AmbientMusicMod/releases

Ambient Music Mod is a good one

Ambient Music Mod (version 210): Port of Now Playing from Pixels to other Android devices

Link