badabing
Let me clarify.
BMAX only uses Wifi or your phone providers data connection to send a very small amount of information to any of
these providers you have an account with and configured with BMAX.
The actual call is made via your normal cellular connection or your phones provider connection so quality is superior to VoIP. Call quality is not dependent on your internet connection at all, as with Sip or VoIP type calls.
Once you send the instructions to any of the providers you have an account with, the provider then calls your source phone you have set from BMAX and you receive a call. This is called "callback". You then pick up the call and you are connected to the destination number you set to call.
All this can happen transparently from BMAX, meaning you can use your phones dialpad and you will be asked if you want call handled by BMAX or not (a configurable call handing option from within BMAX settings).
You can set any number to be your source. Either the mobile you are calling from or any someone else. So yeah, in essence you can connect your mother to talk to her sister abroad and she wont pay a penny. Only some small credit will be debited from your providers account you added to BMAX that in most cases are FREE if you choose the right provider or very low cost.
BMAX was developed for the sake to have real, working solution to make calls - as VoiP type calls tend to be frustrating when you cant hear each other and you need to look for a Wifi connection. With BMAX you just use your cell phone and make calls from it without need for VoIP/sip or WiFi.
One must compare rates from the link above and find the best providers. I have a few accounts with some credit that lasts for a very long time and call the world with my cell. BMAX looks at all configured accounts, the country I want to call from and to, and chooses best account to make a call from for me.
Hope this helps.