att
https://www.h2owirelessnow.com/
https://www.airvoicewireless.com/
verizon
https://www.pagepluscellular.com
sprint
http://ringplus.net/
http://ciaomobile.net/lite/
tmo
http://www.t-mobile.com/
http://www.lycamobile.us/
Ultra
Simple Mobile
RedPocket