Visual notification when time expires

[Carter Dewey]

From a Play Store review:

This works fine if you need a sound or vibration alert on random intervals. I need a visual indicator since I'll be using this in the workplace. Unfortunately it doesn't activate the screen or flash a notification light when the timer expires so it won't work for my needs.

Adding either a notification (which should trigger the LED) or waking the screen would suffice for this. Ideally, both options could be added.