German telephone and internet provider Klatro has launched a new telephone service for home phone and mobile phone users called “Callavista Phone”. This new service is free of monthly fees as well as minimum charges and combines call-through, call-back and internet telephony via a SIP client. It is especially suited for international calls to other countries by home phone or mobile phone or for international roaming calls by cell phone and offers free community calls such as Skype. The advantage of the Callavista phone services to other cost-saving alternatives such as call by call, buying a prepaid SIM card in the host country or using special mobile phone tariffs for international calls: It can be used independently of any provider either by cell phone or by home phone and it is practically available worldwide.