I mean tools to run Erlang apps on iOS and Android, for example.
It has been done.
https://github.com/elixir-desktop/desktop
And a different variant driven by the server typically:
https://github.com/liveview-native/live_view_native
Not to say it is particularly ideal. But it exists.
i see ok. well, erlang is more suited to program gateway nodes in the core of 3g/4g networks.
these nodes handle tasks such as handling mobility (managing handovers as cell phones moves from one location to another etc), data transfer f.e providing ip addresses to your phones etc etc.
as you can imagine, this sort of gear lives deep within service providers network, and each entity handles hundreds of thousands of sessions f.e serving an entire state etc etc.
and these nodes cannot go down taking services/sessions with them.
Erlang (and Elixir and so on) run fine under Termux. Just slap on Phoenix or something and have your GUI in the phone browser if that's your thing.
People that have succumbed to Apple tell me they have facilities at least as good as Termux so you can probably do something similar there.
gui is single(immediate mode) or two(graph based) threaded. with some async going to backend or some app defined compute bounded.
there is no need for actors nor green threads. no need for erlang nor go. languages were not designed for gui(unlike js or csharp), will need a lot of boilerplate for trivial patterns.