We have received multiple tips from many of you claiming that Windows 10 Mobile update is available for Windows Phone 8.1 devices via Update Advisor. It seems the Update Advisor app updates itself first and then the update roll-out begins. You can download the app from below.
Check the screenshot above which comes up when update advisor checks your device and tells you whether the Windows 10 Mobile update is available for your device.
Read what are the requirements and what preparations need to be done before upgrading to Windows 10 Mobile by clicking here.
Click here for the most comprehensive Windows 10 Mobile changelog on web.