Apple has released watchOS 2.0 beta 3 to developers for testing. The build number is 13S5293f.
To install the latest version of watchOS 2 beta on an Apple Watch, download the watchOS 2 beta Configuration Profile, iOS 9 SDK, and iOS 9 beta. Make sure to install iOS 9 beta on your iPhone before updating to watchOS 2.
Developers can download the watchOS 2 beta Configuration Profile from the link below...
Watch OS 2.0 requires an iPhone running iOS 9 or it won't work. Even if you downgrade the iPhone to 8.4 and watch is on OS 2 the watch won't work with the phone
As usual, jailbrakers lose, iOS 2.0 for the Apple Watch will allow 3rd party Apps that will run without needing the iPhone, but if iOS 9 is necessary to upgrade the Apple Watch meaning loosing the iphone jailbreak its a loose loose situation, unless maybe upgrading the iPhone to iOS 9 Beta right now, then upgrading the Apple Watch to iOS 2.0, and right after downgrading the iPhone back to iOS 8.4 while it's still possible and re jail braking, it could work unless the iOS 2.0 Apple Watch will only synchronize with the iOS 9.x iPhone.Another idea is using a different iOS 9 iPhone just to upgrade the Apple Watch to iOS 2.X then disconnect them and connect the Watch to our 8.4 jailbroken iPhone. WILL THIS WORK????
Watch OS 2.0 beta will not connect to an iPhone using anything less than iOS 9 Beta (confirmed via screen shot). I suspect it even requires the latest build, but I'm not sure as it was just released. I've been unable to update my watch so far. I'll try again later today. I don't recommend the beta yet. It killed my watch. As for native apps, there are none and won't be until September so JB away!