Is there any out there? Plus points if it is hackable in any way, but not a hard requirement.
Edit: I am looking for a watch with independent GPS chip, not one that needs to be connected to a phone all the time.
If you use Android then they're completely hackable with alternative open-source firmware[1]. Actually if you follow the link there's a whole list of hackable watches you could check out
Importantly, the tracking works fine without a phone. I would go exercise without having to bring a heavy phone along.
The newer models are more expensive, but have built in routing it seems. Shrug.
I don't use my old one any more and I'd be glad to mail it to you if you want.
https://g.factoryoutletstore.com/cat/1660/Garmin-Fitness.htm...