A free app for Android, by Mario Ostwald.

LED Blinker Notifications is a platform that is designed to display your missed calls, SMS and Gmail messages. If you have no hardware led, the screen is used.

You can customize several settings:  the blink rate, vibration, sounds, the number of repetitions for those flashes.

If your hardware does not have this feature (on-screen LED is always working!), this app can be very useful to you.

You can customize your notifications to be shown over the always on-screen LED and the screen can light up in different colors.

There is an option to turn on the flashlight to help you in the dark and if you have no LED this app can be very helpful for you.

The full version is available here.

The free version does contain ads but a one-time payment should remove it in no time through the lite version.