PPSSPP to UWP (desktop, mobile and xbox)

[TkSilver]

It would probably be somewhat possible.... but also very pointless.

Just because an app is UWP does not make it automatically run on all 3 platforms.

PC:
Really kinda pointless, but the least amount of work needed. All it would do is place restrictions on the emulator that are not necessary since if you want other versions those can just be made as seperate versions without the need to effect windows version compatibility, features, and functionality.

Xbox one: While it is probable that PPSSPP could be made to work on an Xbox one, Microsoft would never allow an emulator to be easily distributed on their console. Without a "jailbreak" or some other way to run unauthorized code on an Xbox one this would be fairly useless.

Windows 10 Mobile: (see Windows phone) Windows phone OS is not Windows 10 (desktop). They do not run on the same types of processors and they do not have the same features (API's). There is 0 advantage in writing a program to run on both platforms besides having a single unified microsoft store entry.