I stumbled over this while watching some recorded live streams from Game Theory.
Kahoot! is a free game-based learning platform. You can create your own Quizes in a couple of minutes or try out thousands of fan made Quizes. Play alone or with others.
The site has it's flaws - Game Theory crashed it a several times due to the high number of players, but it is worth trying, create your own Quiz for Guild Events for example.
If you wanna try: There are a small amount of Guild Wars 2 Quizes playable (this one for example, created 2 years ago). Get your Game PIN and go to www.kahoot.it
Leave some Links to Quizes you created here.