Like clockwork, Apple has been releasing developer betas of OS X El Capitan, watchOS, tvOS, and iOS on Mondays about two weeks apart and then following up two days later with public betas. Today brought beta 4 of OS X El Capitan 10.11.4, watchOS 2.2, tvOS 9.2, and iOS 9.3 to registered developers, and we can expect the public beta versions to drop on Wednesday.
Apple said very little about what is contained in each of the new betas, other than they "contain bug fixes and improvements." The new betas are also accompanied with a fourth beta of new versions of Xcode and Apple Configurator.
OS X El Capitan 10.11.4 provides a way to encrypt individual notes in the Notes app and will let iPhone 6s/6s Plus owners view Live Photos in Messages.
watchOS 2.2 and iOS 9.3 will let owners pair multiple Apple Watches to a single iPhone, helpful if you own more than one Apple Watch. There's also a new layout for the Maps Glance view.
tvOS 9.2 adds support for Bluetooth keyboards, folders for grouping home screen apps, improves on the App Switcher, and adds support for iCloud Photo Library. In addition, the fourth-generation Apple TV will gain voice dictation support once tvOS 9.2 is released.
As we've noted before on Apple World Today, iOS 9.3 will add the highly-anticipated Night Shift mode that can help users to fall asleep faster. The iPad will get multi-user login capability -- at least for education customers -- and CarPlay, Health, and Music have been optimized. It's also expected that iOS 9.3 will let third-party apps add music to your iCloud Music Library directly from an iPhone or iPad without needing to resort to iTunes on a Mac or PC.