Microsoft had originally planned to begin rolling out Windows 10 Mobile to existing handsets in December - but right around the time it was expected to release its new OS, it revealed that device owners would have to wait until early this year for it to arrive.
While there are some indications that the rollout may already have begun on some carriers - or at the very least, that it is imminent - Microsoft hasn't yet made any announcements to confirm that. But the company is likely preparing to do so very soon, and one component of that upcoming announcement may well be a new 'Windows 10 Upgrade Advisor' app that is reportedly on the way.
According to WMPU, citing unnamed sources, Microsoft is working on the new app as a means for owners of Windows Phone 8.1 devices to check whether or not their handset can be upgraded to Windows 10 Mobile.
Purported screenshots of the app state that it "provides information about upgrading to Windows 10 and helps you prepare your phone to install the upgrade."
A further screenshot, showing the app listed on the Windows Store as 'Upgrade Advisor Beta', includes the following description:
The Windows 10 Mobile Upgrade Advisor app will tell you if your Windows 8.1 phone is eligible for upgrade to Windows 10 Mobile. It can also help free up space on your phone so you’re ready for the upgrade. When you open the app, it checks your phone and lets you know if it’s eligible to upgrade, if an update is required before you can upgrade, or if your phone can’t be upgraded. See windows.com/mobilespecs for more information. If your phone is eligible for the upgrade, you may need to free up some space to get it. The app will recommend files, such as videos or photos, that you can temporarily move to OneDrive or an SD card, if you have one installed. Accept the recommendations, or change which files you want to move. You can also delete some files, if you want. If you move files to OneDrive, you need to use the app to restore files back to your phone after Windows 10 Mobile is installed.
It's worth pointing out that the link referred to in that description points to a dead page, and the description itself refers to "your Windows 8.1 phone", rather than the more accurate 'Windows Phone 8.1 device/handset'. Additionally, the app refers to 'Windows 10', rather than 'Windows 10 Mobile' - but it's possible that these inconsistencies are simply the result of unfinished development efforts using placeholder text.
Last summer, Microsoft confirmed to Neowin a list of ten Lumia handsets in line to get the upgrade to Windows 10 Mobile.
Source and images: WMPU