CoinOs's implementation is NWC-only as far as I know. Here's the relevant (Core Lightning) code from their repo:
Here's Alby Hub's LND implementation:
The main ones that support NWC right now are v4vmusic.com, Castamatic, and StableKraft.app. Podverse is adding NWC to their 2.0 version. The other apps have historically used the Alby API directly, but we're working to get each of them to adopt NWC.
GitHub
coinos-server/lib/nwc.ts at master · coinos/coinos-server
Coinos back-end application server. Contribute to coinos/coinos-server development by creating an account on GitHub.
GitHub
coinos-server/lib/payments.ts at master · coinos/coinos-server
Coinos back-end application server. Contribute to coinos/coinos-server development by creating an account on GitHub.
GitHub
hub/nip47/controllers/pay_keysend_controller.go at master · getAlby/hub
Alby Hub - Your own Bitcoin Lightning node: easy, connectable, feature-rich ✨ Run anywhere. Become self-sovereign. - getAlby/hub
GitHub
hub/lnclient/lnd/lnd.go at master · getAlby/hub
Alby Hub - Your own Bitcoin Lightning node: easy, connectable, feature-rich ✨ Run anywhere. Become self-sovereign. - getAlby/hub