Apple today seeded the fourth beta of iOS 9.1 to both registered developers and public beta testers for testing purposes, one week after seeding the third iOS 9.1 beta and releasing iOS 9.0.2, the second minor bug fix update to iOS.

The new iOS 9.1 beta, build 13B136, is available as an over-the-air update and through Apple's Developer Center. Apple has also released a third tvOS beta.

iOS 9.1 offers new features and compatibility updates for upcoming Apple products like the new fourth-generation Apple TV and the 12.9-inch iPad Pro. The iPad Pro ships with two accessories, the Smart Keyboard and the Apple Pencil, both of which are deeply integrated into the operating system.

The update includes Unicode 8, adding support for emoji like the taco, burrito, cheese wedge, middle finger, unicorn head, and more, along with a new Messages option in the Settings app, allowing users to disable photos for their contacts.

It is not clear when iOS 9.1 will be released to the public, but it's likely it will come in late October, coinciding with the launch of the new Apple TV.