We used this when we had cats: https://tabcat.com

It’s expensive up front but works pretty well and no hosting fees. Of course it’s not GPS so you kinda gotta know the general area the cat is in. But it was great for getting the cats in out of the yard. They would hide when it was time to come in until we got this. Worked ok for finding them in the neighborhood as well, just walked around pointing the remote everywhere. The collar tags are nice and small as well.