For GUIs in Elixir you can still use Erlangs wx-module. For this to work, of course, it is necessary that your Erlang release is compiled with wx included.
But for the client side I’d prefer a more lightweight solution that does not pull in a full gigabyte as runtime dependency…
This in mind, I do think, currently the best approach is a JavaScript-application which runs in the Browser and is written in a way that it can work without internet access. This could even update itself silently whenever necessary (and online). Also there are multiple tools available, that can convert HTML5/JS-Applications into native applications for iOS, Android or Win mobile. They might need additional tweaking of the source though.
But if you really want to use the same language in the complete applications stack, I heard about a language called haxe which promisses exactly that, but I never tried more than a hello-world, because I#ve no project which could make use of it.
