Telephone is a VoIP program which allows you to make phone calls over the internet. It can be used to call regular phones via any appropriate SIP provider. If your office or home phone works via SIP, you can use that phone number on your Mac anywhere you have decent Internet connection.

Features:

• Address Book contacts autocomplete
• Sending tone signals (just press numbers on the keyboard during a call)
• Mute
• Hold
• Transfer
• Call waiting

Note: While the software is classified as free, it offers in-App Purchases.

Telephone Pro $1.99
Telephone Pro $19.99