Windows 10 build 17746.1000 has is a continuation with the debugging of Windows towards release. This release candidate is codenamed Redstone 5.
Finally fixed an issue in Windows Mixed Reality causing motion controllers to need to be re-paired after initial setup before appearing in the headset. If you still experience this, please file feedback in Feedback Hub.
A few more tweaks to the Narrator which has continued to be a major focus.
Your Phone app is now available to PCs running Windows 10 April 2018 Update (Version 1803, Build 17134) and later.