Thanks. Note that this thread is for devices which fit over the existing switch and physically move it, so you can use it to make a dumb switch smart without having to do any rewiring.
There are also some switch covers which fit over the existing switch but do not move the switch underneath, and you use those when you have smart lightbulbs and you want to wall switch. But that’s not what’s in this thread.
Anyway, in addition to the ecolink and third reality, there is a new option now which is a robot button pusher called the Switchbot. It basically substitutes for a finger push. They have an integration with smartthings which works quite well in the new V3 app. Do you need both a button pusher device and their little hub to get the smartthings integration. It’s not as elegant for light switches as the other two, but it’s good for other kinds of devices where all you need is that button push, like coffee makers, some televisions, DVD players… I even have one on a blender. So I probably wouldn’t recommend it for a light switch, but it can be used for that.