Attack alerts
If someone is walking a real attack or raid onto one of your villages, the browser should tell you without a refresh.
Stock Travian
You notice incoming by looking at the Rally Point or the village list icons.
Travikas
A sound plays, the village name flashes, and a toast opens with a countdown. Scouts and reinforcements are ignored.
What it is not
It will not wake you at 03:00 if you are not in a play window — you cannot be in the game then. It will not fire for scouts. A refresh will not play the same alert twice.