nostr:npub19j8hqy34pnznsrhzfaljt9jxc8hznhtstdtp4hd7z68znjd3k09qthwcd3 

There used to be one called #Tilt, but development stalled years ago.

There's a #crowdfunding plugin for #Wordpress called wp-crowdfunding. Don't know if it's #FOSS, although it seems you need to shell out $ to offer more than one reward and it only seems to offer #Paypal for payments. I'd love to see other options (#Monero?).

Given I heard WP now federates on the fedi, I imagine this kind of would, too, although I'd love to see something more native Fedi with AP updates etc.