by Jake » 03/22/2013
Freephoneline and Fongo are basically backed by the same system. It's just how customers get to interact and use the system that differs.
With Fongo you have two option (at the moment). One is to use the system via an ATA as your home phone, the other is to use their App for Android or iDevice.
With FPL you can use their desktop software (you will get to download it once you have set up your account), or the other option is to buy the config file (unlock key) for 50$. This basically allows you o connect to the system using your own ATA or SIP client. This could either be a softphone on your computer, a built in SIP client on Android, or a 3rd part SIP softphone.
One of the big differences is testing. You can only text through the Fongo app. You can sign up for a FPL account for free, there are no fees to pay unless you want to buy their config file, port a number, or call an area not covered by their free call areas.
Hope some of this helps, but I would suggest to head over to FPL and sign up for an account. This will probably tell you more than I can by actually seeing it.