Microsoft has released Windows 10 Insider Preview Build 18356 (19H1) to Insiders in the Fast ring. This release is mostly bug fixes, including numerous Night Light bug fixes and a fix for KERNEL_SECURITY_VIOLATION GSODs. Microsoft is also introducing the Your Phone app feature called Phone Screen, which allows you to mirror your Android screen on a Windows 10 PC. This new feature will be available in Your Phone App versions 1.0.20701.0 and above.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-insider-preview-build-18356-released-along-with-phone-screen-feature/