iOS 9 and watchOS 2 introduce a range of new features that will improve apps on both the Apple Watch and the iPhone. With iOS 9 support for TestFlight, developers can now begin experimenting with features like App Thinning, which optimizes apps for specific devices to cut down on install size.
With App Thinning enabled, apps will install faster, launch faster, and will take up less space on a device. An iPhone app, for example, won't need to download unnecessary content designed for the iPad.
watchOS 2 support in TestFlight means developers can begin installing and working with the first native apps for the Apple Watch. Native apps are run entirely on the Apple Watch and should speed up app launch times and performance.
Today's update does not include support for the external testing of iOS 9 and watchOS 2 apps, which means developers cannot yet provide apps with iOS 9 and watchOS 2 features to external beta test groups.
This update adds support for testing upcoming iOS 9 features -- including watchOS 2 apps and App Thinning.For those unfamiliar with TestFlight, it's Apple's iOS beta testing platform, designed to let developers recruit beta testers for their apps to work out bugs ahead of releasing apps to the public. Apple acquired TestFlight from Burstly in February of 2014 and relaunched the service alongside iOS 8 as an iOS-integrated testing platform.
Testers can now choose how to receive update notifications for each app they are testing. Also, watchOS 2 beta apps will install automatically when the "Automatic Downloads" setting is turned on in the Apple Watch app.
TestFlight can be downloaded from the App Store for free. [Direct Link]