The rent stated on the exposés of the Crocodilian website are always the so-called German 'warm rents'. This means that utilities (such as heating, electricity, gas, water, WiFi etc) are all included in the final stated price.
Lots of owners provide a telephone flatrate. This is only a flatrate for landline calls within Germany. Those are also included in the rent, but calls to mobile phone or abroad have to be paid, of course. Sometimes owners also block costly calls, and it is only possible to call within Germany - but to receive phone calls from everywhere.
If there are any extra costs, they will be also stated within the exposé. Sometimes WiFi comes on top of the rent. In most cases, owners also charge a certain amount for final cleaning.
Please always read the exposé carefully - you will find all the information regarding the rent and extra costs on the left-hand side.
Sometimes (e.g. 35 Euro) electrictiy is included in the "warm rent". But if you use more than this, the cost will go up in turn. Especially if you rent for a longer period of time. Please talk to the owner about these issues before signing the lease.