“ Google Voice Basics: About Google Voice
Google Voice gives you one number for all your phones — a phone number that is tied to you, not to a device or a location. Use Google Voice to simplify the way you use phones, make using voicemail as easy as email, customize your callers‘ experience, and more.
Google Voice isn’t a phone service, but it lets you manage all of your phones. Google Voice works with mobile phones, desk phones, work phones, and VoIP lines. There’s nothing to download, upload, or install, and you don’t have to make or take calls using a computer.
Google Voice will let you define which phones ring, based on who’s calling, and even let you ListenInTM on voicemail before answering the call. We use smart technology to route your calls. So, if you’re already on a Google Voice call, we’ll recognize it and use call waiting to reach you on the phone you’re on.
Note: At this time Google Voice is only available in the U.S.“
And another great tool right from the cloud. Unfortunately not in Germany yet, but maybe soon. There a so many Apps I even haven’t heard of.