I have an app that records tracks using the GPS. Currently the watch app can control the iOS app to start and stop a recording, but I would like to know the best way to detect if the watch has an on board GPS. This would allow my app to determine if the watch can be stand alone or not.
Or is it preferred to build the watch apps as stand alone apps even though users with the series 1 watch will not be able to tae advantage of the GPS.
I asked myself exactly the same question. Have you found a way to solve that?
Check to see the device's water rating. In addition to GPS, Series 2 also got a higher water spec.
https://developer.apple.com/documentation/watchkit/wkinterfacedevice/2293683-waterresistancerating
According to the tech spec listings in the following URL, Series 2 and newer have a rating of wr50.
https://support.apple.com/en_US/specs/applewatch
So check this property on WKInterfaceDevice, if 50 rating, then gps!
Good luck.