Presence based on cell phone (iPhone) and wifi

I would like to use presence in HA to not only automate things at home but to also do some intelligent notification based on several location outside the home.

I set up owntracks for presence, but I’m not really satisfied with its updating. The confidence circles are too big, and most of the locations are indoors and thus have poor, or no, GPS coverage. I know I can set up ibeacons to force an update, but that requires buying, configuring, and powering the things.

All of the locations in question have wifi. Is there a presence system that can trigger location based on my cell phone connecting to a particular wifi ssid? It appears that owntracks doesn’t support it, but maybe something else?

I know there are some systems that work with the router, but that doesn’t work for me as I don’t always have control over the routers at those locations.