Not that I know of, but I’m hoping it catches on. I’m too busy with other things to fight with making my own Nostr client, but it’ll end up on my list of things to fund if others don’t do it first. 

 I believe Amethyst does proactive ones kinda like this, if a few of my contacts mark something as spam or whatever, it'll mark it for me, too, without doing anything. It was a bit controversial when first rolled out.