Microsoft has released a new build of their Windows 10 Mobile preview, build 10136, which is focused on improving the experience through a series of subtle "fit and finish changes." Most of these improvements are fairly minor, though Microsoft does state that they've made many changes to the fonts, icons and layout that make the UX feel more complete.
Cortana has also been improved in Windows 10 Mobile build 10136, with Microsoft stating that this version is "very close" to the final design. Flight and parcel tracking has been enabled in this version, and you can now get inline answers to questions surrounding the weather, stocks and currencies.
This new build of Windows 10 Mobile brings a one-handed use mode as well, which can be activated through long pressing the Start button. In this mode, which is only available on devices with five inch displays or larger, the screen will "slide down so you can reach items at the top".
For those that do want to try out Windows 10 Mobile build 10136, Microsoft notes that you will have to roll back to Windows Phone 8.1 (if you're running Windows 10 Mobile build 10080) before you can upgrade. This can be done through the Windows Phone Recovery Tool.
After the upgrade is complete, Microsoft also warns people that a blank lock screen will appear without the date or time due to a missing post-upgrade migration screen. This behavior is perfectly normal, and the company advises that you let your device sit and wait until the lock screen returns to normal before using it, otherwise your phone could end up in a "funky state".