What app uses this symbol?

[1musicLover1982]

Ugh...I can't even figure out how to attach a thumbnail of the screenshot

 

[Rukbat]

See How To Post Screenshots on Android Central.

 

[B. Diddy]

Welcome to Android Central! It's a simple matter of swiping down the notification panel and looking at the app name associated with the notification. If you don't see the app name, then long-press the notification and tap App Info.

If this isn't your phone, then ask the owner to do that.