I've said this before. As much as sending text messages over GMRS sounds like a neato idea, (which it kinda is), it's yet another example of trying to make GMRS something it was never intended to be. As much as amateur radio gets maligned on this site, the list of ways GMRS wants to be like amateur radio keeps growing. Linked repeaters carrying transmissions into other states, internet setups like Zello, and texting apps like Ribbit. The problem is that GMRS has a very limited 5 mhz slice of the UHF band, and it's channelized. Cramming more and more into it is eventually going to overload it. I'm a bit of a purist, so in my humble opinion, leave it alone and use it for, as the sum of all human knowledge, Wikipedia, says, (I say that with tongue firmly planted in cheek), "short-range two-way voice communication and authorized under part 95 of the US FCC code".