How to extract frequent location data from an iOS backup?
I'd like to use it to generate GPX (location+time) output and use it to tag my photos.
Does anyone tried to adress this issue?
Your photos should be tagged if taken by the phone. You can use iPhone Backup Extractor — it will show you location data and times, that your iPhone tagged a location, be that a photo, a message or something else, which may help you for what you are trying to do.
The other option may be to download your google maps timeline if you have this activated: https://www.google.com/maps/timeline
You can manually extract the frequent location data from here, but you will need to convert the files to something readable.