Technically, all devices need to connect to the ST hub in some way. Some can connect directly, others require or can use a separate hub such as Hue bulbs or Logitech remotes that use a Harmony Home hub. These are typically cloud to cloud integrations. All devices need to have a Device Type Handler that tells the ST Hub what the device can do. Finally, there are Smart Apps that can integrate various devices to automate certain things.
In the IDE, you can create a new Device Handler and use the option “From Code” and paste the code in. Once you have a device handler saved and published for yourself, you can assign it to your Foscam camera. Some devices will not be in the IDE and you will have to create one from scratch. You can enter temporary numbers for some of the fields and they will be replaced once you have the proper DTH assigned to it.
I’m typing this all from memory, so I might have missed something. Just let me know if you get stuck somewhere.
So, for your Foscam Camera, I would first do a search for an appropriate device type. Some device types are already built in, others have to be installed separately from community written DTHs.
@eparkerjr created an excellent free DTH
@rboy makes an excellent DTH with live video streaming for the Foscam camera for a nominal cost
Finally, this wiki is another good place to see what’s available:
http://thingsthataresmart.wiki/index.php?title=How_to_Quick_Browse_the_Community-Created_SmartApps_Forum_Section