3CXPhone - FREE VoIP Phone for Windows, Android and iPhone

3CXPhone is a free VoIP phone available for Windows, iPhone or any Android based smart phone such as Google Nexus, Sony Xperia, Motorola Droid or Samsung Galaxy. Connect 3CXPhone to a VoIP provider or to a VoIP PBX (for example 3CX Phone System) to make calls to any VoIP, mobile or landline number.
Installing 3CXPhone is easy and only takes a few minutes. There is no licensing fee and you are not tied to a particular VoIP provider. You can download the version for Windows XP, Vista and 7 here. If you are using Android, you can download it from Google Play. The iPhone version is available via the Apple Appstore.
Features

• Available for Windows, Android and iPhone
• On Windows choose from several popular phone interfaces
• Automatically provision the settings
• Multi-line
• Transfer calls
• Record calls to disk
• Shows personal call log/history
• Supports G.711, GSM and Speex codecs
• Easy to deploy and manage
• Supports standard USB and JABRA headsets (Windows)
• Works with 3CX Phone System, Asterisk and popular VoIP providers