Depends on how big your cat is. And if she’ll wear the device on a collar.
The radius network Dot Ibeacon is intended as a wearable, used at conferences and things like that to check people in various areas. It’s quite light weight. Already have band holder attachements. Not really waterproof, but that’s usually less of an issue with cats than with dogs. And like all Ibeacons you can adjust the distance quite nicely. And so it would only trigger for the cat not for a person.
Assuming that is that the cat would wear it.
Then you would need to set up a device as a receiving station for the IBeacon. Ibeacons are easier to use with iOS devices but possible with android. I don’t know much about android so you would need to talk to somebody Who is using Ibeacons with it.
But you can definitely use Them with smartthings as long as the receiving station app can send a post request, because then you can use the IFTTT maker channel as your go between.
I have a situation at my house " The bus stop problem." I use a wheelchair, and it can take the bus driver several minutes to unload me from the bus. I don’t want my arrival routine going off while I’m still half a block away sitting on the bus. So I use an Ibeacon so that I can catch the arrival events right at the base of my wheelchair ramp to the front door.
Note, though, that this is not going to be the least expensive detection method. Need to buy an Ibeacon and you need to dedicate a receiving station device. So don’t know if it’ll be worth it to you from a budget standpoint. But it should be pretty easy.
http://store.radiusnetworks.com/collections/all/products/radbeacon-dot
And a forum topic discussing Ibeacons: