Apple released iOS 9.2 beta 4 on Wednesday. It’s available for developers in addition to the public through the company’s open beta program, which allows anyone to test the latest software releases, so long as they can stomach the bugs.

iOS 9.2 will deliver new features when it hits everyone’s devices after the beta period, including support for NumberSync on AT&T, and extensions in the Safari browser. It’s not immediately clear what’s new in this latest release, but Apple typically starts to squash final bugs and improve the performance as much as possible as it gets into the later betas and prepares for the full launch.

Developers and public beta testers can find the update through the settings, or in Apple’s developer portal, now.