Apple has now opened the floodgates and is letting all developers submit Watch apps to the App Store. This means any of the 1.2 million apps can now submit updates including Watch apps (using the WatchKit framework), beyond the select partners Apple rolled out last week.
As a reminder, Watch apps come bundled as extensions inside normal iOS apps. This means customers can update the apps in the iPhone ready for the Watch’s release on the 24th. Apple is pointing developers to the submission reference guidelines for more information on this process.