How to play? Popping other peoples bubbles

When browsing the world map you see lots of bubbles. Did you know that as long as they are 7 days old you can still attack them! Bubbles only pop after the person logs in for the first time after the 7 days. You cannot attack from the world map, but you can do it through your muster field by entering the cords manually! You can get lots of free resources this way! Be careful though, any wall defenses or unhidden troops will still defend so watch the might under the bubble!