It does what it was intended to do without problems. What more do you want?
I smell troll.
I don't know, I can sympathize with OP. I thought it was really cool when it came out and started using it even though I'm on a family messaging plan. It seems to
almost work right, it every once in a while, a message gets lost. It almost invariably happens at work (spotty cell service) and, when it happens, it's always something "important" from my wife.
When I try to explain later on why I'm either ignoring her or forgot to do what she asked, I have trouble claiming that I didn't receive the text because it said "delivered"on her phone.
It's not worth the friction it causes in my situation. I've turned it off and still use the carrier now. It, on the other hand, is very reliable - though not free. Sometimes you do get what you pay for...