TapTap VS AmbientMusicMod

Tap, Tap (version 1610): double tap on back of device

This app has double tap with sensitivity adjustment, works perfectly for me with no noticeable battery drain. https://github.com/KieronQuinn/TapTap

Just a quick shout-out of an app I discovered, it's a backport of quick tap for older android versions, but also has sensitivity adjustments and works great for me. Always triggers when I double tap (unlike the originl) and I've never had it accidentally trigger. https://github.com/KieronQuinn/TapTap

That said, some apps do use Material Design 3: Sync, Simple File Manager, Auxio Tap, Tap

Github

Tap Tap provides customizable tap routines

Tap, Tap (version 1600): double tap on back of device

there also is an app named "tap tap" available on GibHub with direct integration as Tasker Plugin.

Have a look at Tap, Tap.

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