Whistle Phone brings free inbound and outbound calling in the contiguous US to your Mac. We also offer international calling at low rates.

Features

• Make and take calls from your desktop or mark yourself as unavailable
• Choose your look and feel from seven different skins
• Has built-in integration with your Mac's Address Book
• Includes two-line calling features, including call waiting and three-way calling
• Forwards your Whistle calls to any phone number via our Follow Me service
• Utilizes Apple's Bonjour technology to automatically discover and call Whistle users on your WiFi network
• Integrates with Growl for customizable missed-call notifications

And, one note: Your best experience is going to be with headphones. Using the built-in speakers and mic at the same time may cause echo.

Note: This application contains in-app and/or external module purchases.