The Microsoft Lumia 635 is one of the phones able to update to the Windows 10 Preview. I go through the tedious process of updating and do a quick run through of the OS.
These are the phones that can receive the preview update:
Lumia 630 Lumia 638 Lumia 635 Lumia 730 Lumia 636 Lumia 830
Check the official post here.
The Lost Digit 