I recently switched to an iPhone from Android (and a brief stint from Windows phone). I've been using Verizon Messages as my SMS/MMS app going back to Android (I travel internationally a lot - saves me a lot of money texting over WiFi).
I installed VZ Messages on my iPhone which seems to work fine as long as I'm well connected, but when I'm in spotty coverage or in a place where I have no data (international airport), it doesn't seem to send/receive. I can go over to the integrated Messages app and send/receive SMS from there. I also have times when I get an alert for a message, but it doesn't show up in the actual message list until I get into a steady data/wifi zone. It does sit in the integrated Messages app.
On the Android platform, it seems VZ Messages sits over the integrated Messages app (I believe it shares the same database) & it works as long as you have cellular signal (even without data or internationally). I'm not sure if the iPhone app should behave the same way?
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