The existing Windows 8 application runs perfectly on Windows 10, but the design paradigms (including both visual style and interaction patterns) do not reflect those of the Windows 10 apps. Users of the Windows 8 app have left reviews on its Store page clamoring for it to be updated for Windows 10. There are new assets and APIs provided by the OS that should be used to integrate the app into Win10 better.
Just some quick commentary on this subject (at least the subject of creating a new UWP app from scratch), since this has come up in some recent user feedback:
We need to remind ourselves of the idea of use cases. The use case for a user on a desktop PC is radically different from the use case of a user on a mobile device or a tablet. Even though it may be possible to create a "universal" app that works on all of these devices, the user experience in the app will have to be diluted to serve the lowest-common-denominator of all the supported platforms, and will end up serving none of the use cases particularly well.
The point of developing native apps is to take advantage of the specific strengths of each platform, and not be burdened by vestigial features from other platforms. On a desktop PC running Windows 10 (or arguably on a Surface Pro), Wikipedia is perfectly usable through a web browser. Therefore, a separate app would be totally pointless.
On a mobile device, however, a dedicated app benefits the user by being tightly integrated with the underlying platform (think responsiveness, notifications, quick lookups, location-aware features, etc), and becomes available at the user's fingertips when she needs it. This is why we have a dedicated Android and iOS team. But as we've seen, the market share of Windows Mobile devices doesn't seem to be growing.
For these reasons, working on a UWP application isn't currently on our road map.
Twitter recently updated their Microsoft Store app with a web wrapper. What are your thoughts about doing the same thing with the Windows app?
While anyone can propose patches for the apps/win8/wikipedia repository in Wikimedia Gerrit I'm not sure either who would have capacity / motivation to review such patches, looking at https://gerrit.wikimedia.org/r/#/q/project:apps/win8/wikipedia
@Daylen: Do you offer to work on this?
(Also note that https://en.wikipedia.org/wiki/List_of_Wikipedia_mobile_applications also lists at least one app that is supposed to work on Windows 10.)
@ksmith mentioned that someone at Microsoft reached out to the Wikimedia Foundation regarding this. I assume the finished project would look something like the image below (I just made using Visual Studio in two minutes, many functions aren't working). If Microsoft is willing to develop the app, I would recommend just having someone at Wikimedia work with them to push the code out through official channels.
Another option is transferring the iOS app to Windows, like what Facebook did with their Windows 10 app. More documentation about this possibility is available at https://developer.microsoft.com/en-us/windows/bridges/ios.
References welcome for ksmith's statement - any links? :) In any case, working on this would require resources. As far as I know the Wikimedia Foundation currently has no resources or plans to support Windows 10. So this requires someone to step up and that is why I asked if you plan to work on this...