iOS 11.3 is a fairly large update that includes some new features, such as messages in the iCloud about device messages away sync and save space. In addition, iOS 11.3 includes many security updates, which is why it is recommended for this reason alone, the update.
ARKit 1.5 adds the first revised version of ARKit, which made its debut in iOS 11. The 1.5 version is able to more accurately map irregularly shaped surfaces, recognize images and place objects on vertical surfaces such as walls. Thus, e.g. Museums filled with interactive exhibits or a movie poster come to life. The real view through the camera when using AR provides a 50 percent higher resolution (1080p) in ARKit 1.5 and supports autofocus.
In the Health App, Apple is adding a new Health Records feature to make it easier for customers with a participating medical facility to directly access their data in the iPhone, even if that medical information is spread across multiple providers. Of course, this only happens with the consent of the user. So far, only US clinics in this cooperation.
Who has an iPhone X, can look forward to four new Animoji. Below is a lion, a bear, a dragon and a talking skull. Who likes it ...
Apple has in iOS 11.3 the promised since early 2018 features for displaying the battery status and the ability to take back any throttling of the system again. This only applies to iPhones - with iPads, there was never the automatic throttling, even if some readers say otherwise. In many cases, it also uses the devices once to reinstall, if the impression is that they have become slow.
Actually, Apple wanted to realize in iOS 11 and AirPlay 2. But this was for unknown reasons nothing. The revised music transfer function should provide a more stable connection than before and allow multi-room audio, which should be driven straight through the HomePod. Apple's smart speaker should also use the feature to allow stereo playback across two connected devices. Unfortunately, Apple had already removed the function in the beta versions of iOS 11.3 quickly. The reason was, the beta testers did not learn and in the final the function is missing as expected.
The update to iOS 11.3 can now be downloaded and installed over the air on all compatible devices. We strongly recommend making a backup either locally or in the iCloud.