I would like to be able to send/receive text messages between my Maxx and my kids' iPads. I have them each set up with Gmail addresses, but there is no phone number associated with their devices. I've looked at several of the free messaging services that claim to be multi-platform, but they all piggyback off of an existing phone number. I can use my Google Voice number on one of them, but that still leaves me a couple of devices short (and you can't get additional Google Voice numbers without tying them to real numbers). Does anyone know if there is a text messaging app that relies only on an email address? Or, is there another way to communicate between an Android phone and an iPad?