Apple has officially seeded the second developer beta for iOS 9.3.3. It’s available for the iPhone, iPod touch, and iPad, and it’s available as an over-the-air update for devices that have been registered to run beta software. While this is the second developer beta of the software for the majority of iOS-based devices, it is the first iOS 9.3.3 beta for the 9.7-inch iPad Pro, which saw issues being updated to iOS 9.3.2 recently.
iOS 9.3.3 is a relatively small update, focused on bug fixes and performance tweaks behind-the-scenes. Apple released iOS 9.3 in late March of this year.
Are you trying out iOS 9.3.3?