Apple has released the third betas of iOS 11.3 and tvOS 11.3 to registered developers. While iOS 11.3 adds a few interesting new features, the third beta seems to mostly consist of bug fixes and relatively minor improvements, following the introduction of the battery health feature in iOS 11.3 beta 2, although iOS 11.3 beta 3 is also now available for the sixth-generation iPod touch, which was excluded from the two prior betas. It is likely that updated…