how about holepunch. p2p keet.io & https://holepunch.to/
Need Kotlin libs for it. Right now all they have is in JavaScript
Hi, bare-kit is now available on Android and iOS. It lets you use the holepunch stack on mobile platforms. I have a working example of both in Objective C / Java, but "Kotlin can call into C using JNI, the same as Java. That's how Bare Kit works on Android." If you need more info, we can talk on Discord or Nostr DMs, or even here.