You could also write your app in Haxe instead and cross compile to Javascript, Python, C++, Java, Lua,...
I ported an entire AS3/Flash game to Haxe that my friends had written during our college years, as a kind of "thank you" present for ten years of friendship (adding mobile, cross-platform, gamepad controller, netplay and other things).
While the tooling was spotty, I found the experience wonderful! Haxe felt like a decent language with laudable goals and a nice community.
I hope one day I find another reason to work with Haxe.
Does anyone have any project that is using Haxe in production? Would love to hear about such stories!!
I used it a long long time ago on one of my first freelance gigs (with a PHP target). It was already quite solid and saved me the need to use a PHP framework.
I also remember using it as a typed javascript pre-compiler, at a time where FB Flow and MS Typescript were still fighting over developer mindshare. I would probably still use it if TS didn't take over the ecosystem entirely.