Microsoft recently updated the document in support of the announced Windows Phone 8.1 app store will be closed from December 16, 2019.
Microsoft said support for Windows Phone 8.1 system in a July 11, 2017 ended as a vertex support processes end, Windows Phone 8.1 app store will be December 16 close, the use of Windows Phone 8.1's Lumia phones on this date after We can continue to work, but can not download, install applications and receive updates. Although the installed applications can continue to run, but Microsoft warned that once the application is removed from the device, you can not re-install the application. Note that here, including resetting the phone and use the Windows Device Recovery Tool (WDRT) will lead to the disappearance of all applications can no longer be installed.
Windows 10 Mobile version temporarily affected, some models of Lumia phones can be upgraded to Windows 10 Mobile, but users must download Windows 10 Mobile Upgrade Wizard application before December 16.
Moment to upgrade to Windows 10 Mobile phone models Lumia 430, Lumia 435, Lumia 532, Lumia 535, Lumia 540, Lumia 635 (only 1GB RAM variant), Lumia 636, Lumia 638, Lumia 640, Lumia 640 XL, Lumia 730 , Lumia 735, Lumia 830, Lumia 929, Lumia Icon, Lumia 930 and Lumia 1520.
After this date, Microsoft will stop support for the conventional version of this operating system version. Therefore, Microsoft recommends some can be upgraded to Windows 10 Mobile's Lumia phones to upgrade as soon as possible, but at the end of maturity also means that the operating system will no longer be updated (including any other security updates), although the store is still in operation.
Windows 10 Mobile has been considered to be out of the operating system because its market share is currently less than 1%, in Microsoft's guidance, these users have moved to the Android platform. Considering the number of Windows Phone users are now, in fact, only a handful of users are affected.
In addition, with Surface Duo dual-screen Android phone's release, Microsoft is trying to Windows mobile platform almost ended up.