Are those holepunch based or just Pear Credit?
1. https://vdo.ninja for browser-to-browser video conference calls using websockets - can self-host the handshake server - see https://docs.vdo.ninja
2. https://wormhole.app for anonymous file transfers with e2e encryption (p2p in the works)
3. https://picfinder.ai for hyper fast text2img idea generation
4. Pear Credit for individuals and businesses to offer their own fee-less gift cards / reward points / currencies via p2p Lightning-style channels -- without a blockchain and all the work and fees required to maintain a single authoritative global state. Double spending is discovered, not pre-empted, and this trade-off enables an akshully decentralized system of ledgers, just like Nostr.
Discussion
Just Pear Credit, but thanks for adding to the list ;-).
5. Holepunch
VDO.Ninja uses websockets, as does Nostr, but there is no reliance on a relay server -- just a handshake server which opens the websockets connection directly between you and your peer(s) web browser.
It's completely anonymous, as in no public keys or unique identifiers. Which reminds me!
6. https://simplex.chat a Direct Messenger without User IDs (!) that appears even more secure than Session. You'll need Android 10+ to run the Android app, haven't tried the iOS app.
I like holepunch a lot tbh.
We are using it in our productive loans marketplace.
we use Hyperbee for project and loan books.