You can change when to flash and which apps will flash the LED when there are new notifications. 
	 
 
  
 
	 -  
		  From the 
				Home screen, tap 
				. 
			  
		
-  
		  Under 
			 Notification, tap 
			 Flash notifications. 
		   
		  Choose whether to always flash the LED or flash it only when the screen is off. 
		   
		
-  
		  Tap 
			 App light notifications. 
		   
		  Choose which app notifications you want the LED to flash for. 
		   
		
 
		Tip:  In other apps, check their settings to find out if they have an option for flashing the LED.