Make sure you go to settings on your iphone and turn on IMessages. It's likely been on and probably have been using it without knowing. It's through Apple not Viper or other outside companies phone companies. I have unlimited text msgs with my service so it doesn't matter whether I used IMessages or texts within US but would incur international text charges for any texts to #'s outside US. The international rates are a killer!! With IMessages, there's no charge for texts to other Iphones and there's no limit. If you're in a wifi zone, Facetime calls do not eat up your minutes either. There are IMessage Apps on the Iphone, Ipad and Ipod touch. I still use my Ipad a lot. Mainly for watching videos and emailing. I no longer have a laptop. The IMessages work like regular texts but you'll know it's IMessages when it's sent in blue color instead of green. I hope you understand what I mean by green and blue texts.
I sent you a text, which will arrive in white color. If you reply, it will show blue if you turned your IMessages on before replying instead of green.