alt Hacker Newsvoip.ms requires setting up SIP credentials and configuring a softphone (or their app). Great for technical users who want maximum control and lowest rates. Voklit is for people who wish to download an app / use the browser and start calling immediately without touching any settings.
You can do that with Google Voice for free and much lower rates. US/UK/Aus are 1 cent per minute versus 5 on your system, thats your competition.