Cannot speak to Flood Sensors but other sensors, such as the a Smoke Detector, does send a notification out to the App.
On Android you have to double check that you are allowing notifications from the Almond App, same thing in IOS, you must specifically allow the notification.
The notifications show up both in the app itself and in the notification area on the phone and/or iDevice.
As for triggering events, again, using the Smoke Alarm as an example, I can write a rule that triggers a second siren when Smoke is detected or the battery drops below some percentage. I can also cause this same trigger to flash all the lights in the house, turn the hue bulbs red or flash the outside lights repeatedly.
