What app does this notification icon belong to? Upper left (x shouldn't be there). Looks like a chat bubble or ribbon. Thanks!!
I don't recognise the icon, but:
If you drag down the notification bar you should be able to tell:
Before Android 7.1/API 25 (or maybe 7.0/24), if you long click it shows which app it's from. Also if you click the (i) button it takes you to the notifications settings for that app.
With Android 7.0/7.1, you should be able to see the app name as a header for the notification. Long clicking shows the notifications settings there in the notifications item directly.
With Android 8/API 26 you can also see the app name as a header. Long clicking shows which "notification channel" (new from API 26) the notification belongs to, and clicking "MORE SETTINGS" will allow you to see all channels and set the notifications settings for each channel specifically as well as for the app overall.