*nufone
(This is unrelated to Nufone.)
VOIP to PSTN as well as PSTN to VOIP service provider with voicemail.
Subscribers to this service get a public phone number that people can call (only in “selected cities” in Germany per RegTP ruling). While powered by Sipgate, the terms of use are bit different. *nufone requires a monthly fee which includes unlimited calls to fixed phones in Germany, calls to mobile/celluar phones are slightly cheaper and they require the use of a special POT-to-VoIP adapter, others are not allowed. (The adapter is provided by *nufone.)