GPS vs. Cellular
I‘m looking at a series 3 and want to know the difference between GPS and cellular. With GPS only can I use apps like Map my run and can I connect my Bluetooth headphones and play my downloaded music while my phone is left behind?
There is little difference between GPS and cellular. Think about your phone.
If you don't have cellular, you obviously cannot use cellular data. However, your Apple Watch can still track your location using GPS.
Anything else that doesn't require internet on the Apple Watch is possible for use without an iPhone with GPS models.