Apple yesterday released the fourth developer beta of macOS Catalina while the fourth developer beta for iOS has arrived today with an over the air (OTA) update.
Last year Apple released 10 developer betas for iOS 12 which means we are half way to a stable or official iOS 13 release.
This developer beta contains bug fixes, performance improvements and some new features. Detailed description on this update can be found here.
Read on our coverage about iOS 13