Apple today seeded the fifth beta of an upcoming iOS 11.3 update to developers and public for testing purposes, one week after seeding the fourth beta and three weeks after the release of iOS 11.2.6, an update that addressed a bug causing iPhones and iPads to crash when a character from the Indian language Telugu was rendered improperly. You could update in 3uTools directly without losing data.
And here are the iOS 11.3 major new additions in a quick list:
ARKit 1.5
New Animoji
iMessage for Business
Health data
Battery health
Apple Music
HomeKit
Advanced Mobile Location (AML)
Messages in iCloud
Registered developers and public user can download the new iOS 11.3 beta from Apple's Developer Center or over-the-air once the proper configuration profile has been installed from the Developer Center.
iOS 11.3 will be released to the public in the spring. Spring kicks off on March 20, so the update will be in testing for at least another couple of weeks.