Telephone allows you to make phone calls over the Internet or your company’s network. If your phone line supports SIP protocol, you can use it on your Mac instead of a physical phone anywhere you have a decent network connection.

Features:
• Address Book contacts autocomplete
• Multiple accounts
• Sending tone signals (just press numbers on the keyboard when call window is active)
• Mute
• Hold
• Transfer
• Call waiting
• Making calls by clicking sip: and tel: links

Patronage:
Telephone is free and all its features are available to you. Please consider buying an optional subscription to make ongoing development possible. There is a monthly and a yearly option for $0.99 and $10.99 respectively (the prices are for the US store). The subscriptions can be cancelled almost any time based on the App Store subscription rules.

Requirements:
OS X 10.10+
To set up Telephone and make calls you need an account at a SIP provider or at your company’s phone server.
Intel