Application 1 has a Ed25519 keypair
Secret key private 3085c7405a88a968133e813e9f638a7d9b2e8088fe717ca535cc24d90b59815d
EndpointID or public key, for connecting to you: 274d4c656f064d4c59fffe7db38d6bf90d63cb087d0b2afd2cfa534334f7071c
and for connecting to App 2 you need to know the other endpoint id, no friendly "dnsish" name involved.
https://en.wikipedia.org/wiki/Zooko%27s_triangle
A mapping from a scarce but human readable name to a non-scarce but not human readable name would't be that hard, but we haven't done this yet.
If we do it it will probably be an additional crate reusing some of our infrastructure, not built in to iroh itself. There are a lot of use cases where the non human readable names work perfectly fine.
We would implement two versions, one using DNS and one using an appropriate decentralized system like ENS.