Vodia Networks is described as 'Vodia Phone app is a free add-on for your Vodia PBX that lets you connect to your account on your Vodia PBX. Starting with Android 5.0 Lollipop, based on the WebRTC technology'. There are more than 25 alternatives to Vodia Networks for a variety of platforms, including Linux, Windows, Mac, Online / Web-based and Android. The best alternative is MicroSIP, which is both free and Open Source. Other great apps like Vodia Networks are Asterisk (Free, Open Source), YakYak (Free, Open Source), 3CX Phone System (Freemium) and Facechat (Free).
FreePBX is a web-based open source GUI (graphical user interface) that controls and manages Asterisk (PBX), an open source communication server. FreePBX is licensed under the GNU General Public License (GPL), an open source license.
Telephone allows you to make phone calls over the Internet or your company 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.
FreeSWITCH is a scalable open source cross-platform telephony platform designed to route and interconnect popular communication protocols using audio, video, text or any other form of media. It was created in 2006 to fill the void left by proprietary commercial solutions.