Apple today seeded the second beta of iOS 9.1 to registered developers for testing purposes, two weeks after seeding the first iOS 9.1 beta following its fall "Hey Siri" event and one week after releasing the first version of iOS 9 to the public.

The new beta of iOS 9.1, build 13B5119e, is available as an over-the-air update and through the Apple Developer Center. Apple has also released a second beta of tvOS, build 13T5365h.

iOS 9.1 includes new features for the iPad Pro, adding support for accessories like the Smart Keyboard and the Apple Pencil, both of which are deeply integrated into the operating system. It also includes features that will allow the iPhone to interact with the new Apple TV.

iOS 9.1 also includes Unicode 8, adding support for some long-awaited emoji like the taco, burrito, cheese wedge, middle finger, unicorn head, and more, plus it includes a new "Hey Siri" Settings feature that lets the "Hey Siri" command be customized for an individual user's voice. On-demand voice activation for Siri using the "Hey Siri" command is a new feature in the iPhone 6s and the iPhone 6s Plus. On older devices, "Hey Siri" only activates Siri when plugged into a power source.

It is not clear when iOS 9.1 will be released to the public, but it's likely it will come in November, alongside the launch of the iPad Pro.

What's new in iOS 9.1 beta 2:

Messages - There's a new Messages option in the Settings app that allows users to disable contact photos.