What app is it ?

[Break6]

https://www.fotosik.pl/zdjecie/usun/cX9NLqPWtELhwwtYbomWZmyueL4OBv

 

[davidnc]

https://www.fotosik.pl/zdjecie/usun/cX9NLqPWtELhwwtYbomWZmyueL4OBv

Pull down the notification shade , to see .

 

[B. Diddy]

Welcome to Android Central! This is your phone, right? If you swipe down the notification panel, you should see the details of the notification.

"UE" might refer to the headphone/speaker company Ultimate Ears?