As part of an extensive hands-on by Ariel Adams, the piece shines some light on how the Apple Watch is controlled and managed. At the media event, Apple showed a wide variety of watch apps … but did not mention how they get onto the watch itself.
Adams’ post says that users download Apple Watch apps through a central hub app on the iPhone. Rather than having an App Store UI on a tiny watch screen, users install content on the device from their phone. This is similar to how iPods are managed via the iTunes app on a Mac or PC.
Apple Watch users will install an Apple Watch app on their iPhone, which will be used to download apps onto the watch as well as likely manage Apple Watch settings. A user’s iPhone is also used to help with computational demands. Apple cleverly pushes a lot of processor needs to the phone in order to preserve Apple Watch battery life.
Apparently, the phone will also dedicate some of its processing power to handle complicated or computationally-intensive tasks. This means that the Apple Watch battery can be drained as little as possible. For instance, the iPhone may do the deep analysis of incoming health data sending only the results to the Watch, for display. Apple has vaguely suggested that the Apple Watch will have about one day of battery life.