It's not a gateway. It's doesn't do much.
The concept is great. My kid can has more freedom around the neighborhood. She's learning basic electronic communication, asking us if she can go to a friend's house or having to respond when we tell her it's time to come home. We can leave her home alone, and still have a way to contact her (we don't have a land line).
But the Gizmo itself sucks. Battery doesn't last all day. The app is a pain to use (you need the app to text). The location is sometimes wrong (she almost got in big trouble one day when I thought she had crossed over a busy road that she knows to not cross - but another parent confirmed that she never left the nearby playground).
I don't know if there's an alternative out there to look into, but the idea is great.