The default app launcher on the Galaxy S8 and S8+ can show unread notification badges on respective app icons. This makes it easier for users to know which apps have notifications that they haven’t checked out yet. However, it can also get pretty annoying when apps bombard users with useless notifications,
It’s quite easy, actually, to clear notification badges from app icons without opening the corresponding app. You just need to long press the app icon (either from the home screen or from the dedicated app drawer), and a pop-up menu will appear. Click on Clear Badge option from the menu, and you’re done!
You can read more tips and tricks related to the Galaxy S8 and S8+ here.