HTC U11: How to control the LED notification light

You can change when to flash and which apps will flash the LED when there are new notifications.
  1. Go to Settings > Sound & notification
  2. Under Notifications, tap Flash LED for notifications
  3. Choose whether to always flash the LED or flash it only when the screen is off
  4. Tap Manage LED notifications
  5. Choose which app notifications you want the LED to flash for