qNightLight is a simple mod to notify you when your warlock procs Nightfall. The in-game sounds/alerts just weren't cutting it for me, and in the heat of battle I often didn't watch the buff timer. So, I didn't know when the buff started nor when it expired :)
This mod will play up to 4 warning sounds: Start, Early, Late, expired. You can choose from the Game Menu | Interface | AddOns | qNightLight options panel which of these you want to hear.

