I like Wi-Fi Matic (https://sites.google.com/site/wifimaticapp/ https://sites.google.com/site/wifimaticapp/). It uses the phone network cell identifiers instead

I like Wi-Fi Matic (https://sites.google.com/site/wifimaticapp/ https://sites.google.com/site/wifimaticapp/). It uses the phone network cell identifiers instead of GPS (so it works even where you can't get a GPS fix), and auto-learns the cell identifiers which can be seen in the range of your wifi networks. And its source code is available (I originally found it on f-droid).