Oak Node has had Shadowy LN Tips since 6 months or so: nostr:note1qqqg4tylv66ecf3cdr7tudhvqq03furkggvaxh54kyf7f0n9mp6qzrlhaa

Lets you "zap" any note by simply liking it. Works from any Nostr client. Sats sent non-custodially, from your own Umbrel.