Some Wi-Fi devices, like some Wemo devices and some iHome devices have official SmartThings integrations.
For others, it just depends. See the following FAQ (the thread title is a clickable link)
Here’s the official compatibility list. That also shows other sensors:
And here is the FAQ on the Xioami devices:
FAQ: Help! New to smartThings: will Xioami/Aqara sensors work?