Doorbird is a WiFi doorbell from a company that has been making WiFi video intercoms for awhile. They’re just designing one for the single home market. Mains-powered, which is good for WiFi, but more difficult to install.
It won’t integrate with SmartThings directly as yet. You might be able to make it work like people make the Foscam cameras work, I’m not sure.
They have announced that they are “interested” in HomeKit, but haven’t done anything with that yet.
For more video doorbell discussions, see: