PC Telephone Software Download. Free SoftPhone for VoIP SIP ISDN USB. Cheap PC to Phone and Fax calls over the Internet. TRx Single Line Call Recorder TRx is a phone call recording program for Windows, Mac OS X and Windows Mobile devices. This phone recording software allows you to manually record telephone calls and can also work as a caller ID display system as well as allowing you to put calls on-hold and play on-hold messages or music. There are lots of apps you can use to make free internet phone calls. Google Voice is one example, but there are many others that give you a real phone number that rings the app you install to your phone or tablet. If it's too low or inconsistent, you’re not going to get a good VoIP connection no matter how good your provider is. The key is to test your Internet connection to ensure it is VoIP ready because 9 times out of 10 any problems with your voice calls will be caused by network congestion in your home, business, or Internet Service Provider.