This topic is taking unexpected turns, awesome!

I am indeed programming this project with Qt, which I find well designed and providing great libraries along with extensive documentation. The GUI design tool is quite neat and really easy to use. I think I prefer to carry on as far as possible with this tool in C++ before shaking things up and going for another language.

I believe whatever language I'll use for the future evolution of this app will depend a lot on how my career as a developer progresses and what technologies I'll be exposed to.

Also, as I'm very interested in iOS development, I'm currently learning Swift (you can see the code on my Bitbucket page for an X-Wing reference app for iPhone I made for my personal use. This will never hit the App Store as it uses pictures of copyrighted material, but if you have a Mac with Xcode feel free to download and compile it for yourself). TournamentDroid for Mac will probably be my first foray into macOS development...

Having programmed in many languages including C++ and C#, I would also consider C# an upgrade. So much C ballast has been thrown out and it offers much functionality that is only available in C++ with additional libraries. I think the OP mentioned programming with Qt, which goes a long way towards alleviating the shortcomings of C++.

I'm happy so long as the pros and cons are properly explained. Sure, it's easier to write non-performance critical desktop applications in Java, C# or Node.js than it is in C++, but you lose a lot of control and performance, which means C# cannot replace C++ in certain domains. Hence I'd rather people list the pros and cons and let individuals figure out for themselves whether it suits their needs.

If I wanted a cross-platform (desktop and mobile) app with a rich GUI, I might also consider using Unity Game Engine (which uses Mono) but you're not required to use C# for that.

Agreed that List Juggler outputs would be amazing if they can be implemented.

Also, just a question in general - why do people always want Android versions? I can understand Mac OS as many people have laptops but do people actually run tournaments on Android tablets?

From my point of view dealing with developers in tech (as opposed to traditional computing environments like enterprise, industry or gamedev), the majority seem to use Mac OS as it has better compatibility with linux servers and developer tools than Windows does, and Ubuntu desktop occasionally throws weird problems with hardware.

From my perspective in western Europe, the traditional computer is being replaced by the tablet. I have a friend who lives in a block of flats. Of the 6 flats in the block, 5 households have tablets and only 1 has a computer (in addition to tablets), which is used professionally for spreadsheets. This is a very small and specialised sample size so you should not read too much into it. Geeks and hobby game TOs are probably more likely than average to have a traditional computer.

Good point about 'modern' PC usage. I guess I am sort of lost in the nerdy world of laptops and power-gaming PCs still! I would be interested in seeing what proportion of tournament organizers would like an Android version as this comment seems to pop up now and again but I have never been to an event using anything other than a laptop or the store PC. Having said this I do now a few stores that use tablets now and have those weird square plug in credit card swipe things. Maybe as you say, tablets are the way of the future.