Microsoft has released a new preview version of Windows 10 Mobile to Windows Insiders in the Fast ring



From Windows Central:

What's Fixed

We have fixed the issue that caused the Start experience to become corrupted (garbled) after upgrading and restoring a backup from a phone that had a different resolution.
You should now be able to set your default save locations via Settings > System > Storage and it will correctly reflect the current storage settings. Your SD card should no longer show up as a garbled name in Storage settings either.
Moving apps to a SD card should no longer cause those apps to crash.
We've made improvements to the Messaging + Skype app – through both app updates via the Store and also on the server side.
This should be seeing less resuming/loading text when switching apps.
The physical camera button should be working again if it wasn't working for you before.
Apps and games should download from the Store more reliably.

  Windows 10 Mobile preview build 10586 now available for Fast Ring Windows Insiders