Android has handled notifications in pretty much the same way since its inception. Oh, there have been refinements over the years, but you go to the same place for notifications. That's changing in Android O with Notification Dots. You've probably seen something like this on custom launchers, but this is much more integrated with the OS.

Notification Dots appear on apps when they have notifications active in the notification shade. The dot takes on the color of each icon, and a long-press on the icon pops up a preview of the notification that you can act on. Additionally, the dot goes away when the notification is cleared in the shade.

Google says Notification Dots are extremely easy to implement in apps. Hopefully that means developers will swiftly add support and use Notification Dots to do neat stuff.