Unfortunately, there is no integration as yet. Note that the smartthings hub itself does not have Wi-Fi.
There are many inexpensive Wi-Fi pocket sockets now available, but most of them don’t integrate with anything else.
In order to be able to integrate with smartthings, a Wi-Fi device needs one of the following:
One) an open API for cloud to cloud integration
Two) an official LAN integration
Three) an IFTTT channel
You can write to the G – Homa support and ask if they have an open API. I didn’t see one mentioned on their website. Or IFTTT plans.
Meanwhile, you can suggest it in the forum “suggest a device” topic. That would be the first step to 2) above.