Apple on Monday seeded the first beta of iOS 9.3.3 to developers. Registered iOS developers can grab the new build, which is labeled version 13G12, from the Apple Developer Center, or via an over-the-air update on a compatible device with the latest software.
The update comes just one week after iOS 9.3.2 was released to the public, which brought about a Bluetooth fix for iPhone SE models and other improvements. As you can see in the screenshot above, the 1.4GB iOS 9.3.3 update has also been earmarked for bug fixes.