So this could be used as a streamlined way for client devices (mobile phones for example) to phone home to servers (google.com for example) with user data and bypass some local network controls? (DNS block lists, for example)

Is there an android SDK available?

I’m thinking similarly. Seems delightful for malware development and exfil. But I haven’t confirmed how the actual connections are made.

Yes there is an Android SDK: https://docs.iroh.computer/languages/kotlin