Okay.

So I'm first trying Biketool's suggestion.

I signed up on linphone and now have the following account:

Sip identity: s**********d@sip.linphone.org
Username: s**********d
Email: j****.s**********d@gmail.com
Domain/Proxy: sip.linphone.org

I tried to link this account with my phone after installing their app.

"We have sent you a SMS with a validation code to your phone number:"

No 4 digit code was given on my end to enter though.

Can I not validate my phone when all I have available is Wi-Fi?

Do I need a cell phone provider (such as Sprint/Verizon) to activate this?

The nearest cell tower is about 25 miles away from my home.

Thanks for the help.