Showing my shared Google Calendars on iOS*

Anita and I have a few shared Google Calendars and for some reason they were no longer showing on my iPhone and iPad.
This 'may' have had something to do with me trying to get rid of some phantom events but that's another story.
All my search results were pointing me at m.google.com/sync however that was a deadend as I have my google accounts set up as google accounts rather than exchange.
This was frustrating me for the last few days until I used a slightly different set of search terms which resulted in https://www.google.com/calendar/iphoneselect !

From here you can bypass the whole exchange thing and directly set the calendars (shared and owned) that will sync to all devices.

Happy day :)

*or any other CALDAV device