Apple has released the third beta versions of iOS 10.3.3, macOS 10.12.6, tvOS 10.2.2, and watchOS 3.2.3.
These minor point release betas are focusing on several bug fixes and minor refinements and, unlike the separate concurrent beta testing of major system software releases, the point release betas are not expected to include any significant new features or abilities.
Users enrolled in the beta testing programs can find iOS 10.3.3 beta 3, macOS 10.12.6 beta 3, tvOS 10.2.2 beta 3, and watchOS 3.2.3 beta 3 now through the respective software update mechanisms on each device.
Do note these beta builds are entirely separate from the simultaneous beta releases being tested of iOS 11, macOS 10.13 High Sierra, tvOS 11, and watchOS 4. The public beta versions of these major beta releases will be available later in the month, though technically anyone can download and install iOS 11 beta right now it is not a good idea to do so.
Apple typically goes through multiple beta builds before releasing a final version to the general public, perhaps suggesting that iOS 10.3.3, macOS 10.12.6, tvOS 10.2.2, and watchOS 3.2.3 will be released later in the month or next month. Meanwhile, iOS 11 is set to be released in the fall, along with a fall release for macOS High Sierra, tvOS 11, and watchOS 4.