You can also use Termux, which by default isn’t quite a full Linux distro but it’s close and you can use proot to have a full one

If Termux is enough for you the benefit is that it is quite a bit faster than userland.tech. There is also Nix for Termux which provides a lot more packages.

Wow. This is amazing. Just got a server-side Java application running in the Alpine Linux and was able to access it with the normal browser via localhost. Impressive stuff :D

Are you one of the developers? As I'm really curious how this works.