You don’t actually need a SmartThings Hub any more (this is new) unless you are going to use zwave or zigbee devices. If you were only going to use Wi-Fi devices and cloud to cloud integration, you don’t need a SmartThings hub at all. This is because of a major change with the most recent generation of the app where they now assume that many people will be using it who just have a Samsung TV or smart appliance and some Wi-Fi devices. But you don’t have to have the TV either. The account is now fine with you not having a hub. But you do need to set up a smartthings account.
(Like I said, this is all very new and since most of the people in this forum already had their hubs, It’s a little hard for most of us to wrap our heads around. But you no longer need to have a hub.)
@tgauchat Is one of the action tiles developers. I’ll leave it up to him to discuss whether not you can use action tiles without a hub. It’s a very popular third-party dashboard app in the community, but again, I would say 99% of us in this forum have hubs right now, although I do expect that percentage to change over the next year.
As was mentioned, there is no official integration with the D-Link smart plugs, but you can use them through IFTTT to connect to your smartthings account. (Again, no hub required now to do this. )
I’m pretty sure your Sonos speakers will work.
Please be patient with us as we are all navigating the new platform concept, which includes a new app, a new cloud, and again, the fact that you no longer have to have a hub unless you want to use zwave or zigbee devices.
https://support.smartthings.com/hc/en-us/categories/115000465506-SmartThings-App
When you look at possible new devices, just keep that in mind. As soon as you select a zigbee or Z wave device, you will have to commit to a hub as well. 