I'd suggest Apple's FaceTime, but that only works for calling other iOS devices. (Disclosure: My work number is on Google Voice, so ditching those digits won't work for me.) ...

Google’s Voice service allows unlimited free calling to the USA and Canada. With Internet connectivity, you get email notifications for voicemails, and can query WolframAlpha by voice.

Google Voice offers three pricing plans for business users, ranging from $10 to $30 monthly per user. With unlimited calling and texting for just $10, the Starter plan is one of the most cost ...