Most such emulators have Internet access on the IP level. Therefore, this is a very cheap way to test anything on the Internet.

    apk add nmap
    nmap your.domain.com

However, the speed is heavily throttled. You can even use ssh and login to your own server.

It can also be used as a very cheap way to provide a complete build environment on a single website, for example to teach C/C++. Or to learn the shell. You don't have to install anything.