Amen is a Berlin startup getting plenty of attention for its simple, fun iPhone app (there’s no Android version yet) that allows you to argue over opinions.

Everything from the worst movie genre ever, to the best song ever, to ‘The best excuse for relationship issues ever’ is being discussed on Amen every day by its keen band of early-adopting users.

What’s it all for though? We spoke to Amen’s CEO and co-founder Felix Petersen at the How To Web conference in Romania to find out more about how the service works and how it could become a go-to place for discovering the best or worst… anything. He also explains how Amen differs from Oink, Kevin Rose’s recently launched, much-hyped app with a similar aim.