The value-added tax (VAT) is 19% in Germany. Service and VAT are included in the price in restaurants, bars, etc. all over Germany. Still, it is typical to "round up" the amount.
It is customary to leave a tip to thank waiters, valets, bellboys and other service providers. At restaurants, bars and coffee shops, it is customary to leave 5-10% of the total amount of the bill.