This app lets your Philips hue lights flash in a predefined color, whenever one of the selected apps posts a new notification.
For example, your living room light blinks in red, if you receive a new e-mail and your office light flashes in blue when you get a text message.

Requires a Philip hue bridge and Philips hue lights (or LivingColors lights)

This app is open source: https://github.com/j4velin/HueNotifier