Some Bitcoin wallets, like Breez and Phoenix, contain a full Lightning client inside. These apps still need an external full ₿ node but the app manages its own channels.
Now, to make #nostr more resilient I would love to see clients that have a build in relay. It doesn't have to store and share a lot of stuff, but at least your own messages, as well as maybe a random or selective set of 5-25 of your contacts’ messages.