If you want to tame your Android notifications, you can do so right from the lock screen or home screen. At least, you can if you're running Android 5.0 or later.
Next time you get a notification from an offending app, just touch and hold the notification for a couple of seconds. A growing circle will expand from where you touch it, changing the notification from the default white to a darker color. Two different icons will appear: a settings gear and “i” in a circle.
When you touch the gear, you’ll head right into the app’s notification settings. If you don’t want to hear from this app anymore, you can block it entirely by flipping the switch next to Block.
Or if you this is an app you want to make sure you always get updated about, select Priority. The middle ground is Sensitive, which hides any information you may or may not want to pop up when the device is locked, like the contents of a chat conversation.
The “i” icon will take you to the app’s settings. From here you can make any adjustments to the app built in by the developer.
This new system is available in Android Lollipop. You can touch and hold a notification to trigger these actions either from the lock screen or by swiping down from the top to open the notifications shade.