Yes, if you choose a secondary messaging application, put it on each of your phones, and keep the app running on your phone in the background. An App such as Skype would allow texting and voice calls between members of your family over Wi-Fi. However to use something like this in all situations, both parties need to be connected to a wi-fi site, OR have a cellular data connection. Depending on your situation, you may wish to have a data plan for your phone, so it will work anywhere, and leave the teens to search out wi-fi, when they need it.
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