Someone once told me that if everyone has one feature that they really care about and want to see, mine would be ARM64 support for UWP apps. This isn't true, as anyone who knows me knows that it was always OneDrive placeholders, but ARM64 is something that I've tried to stay on top of, since it makes absolutely no sense that a developer can't compile an ARM64 UWP app.
To be clear, when you compile a UWP app, you get three packages: x86, x64, and ARM32. The Windows Store downloads whichever package corresponds to your device.
Windows 10 Mobile - Windows 10 Mobile is a 32-bit operating system. Devices like the Microsoft Lumia 950, 950 XL, HP Elite x3, Alcatel IDOL 4S, Acer Liquid Jade Primo, and more have 64-bit chipsets, but Microsoft never bothered to build out the OS to fully support it.