AIUI you'd have to since extensions have to be signed by an Apple Developer certificate, which is about $100/yr https://developer.apple.com/safari/extensions/ h

AIUI you'd have to since extensions have to be signed by an Apple Developer certificate, which is about $100/yr https://developer.apple.com/safari/extensions/ https://developer.apple.com/safari/extensions/ Now, if you, personally, wanted to install it I believe there's a locally signed cert issued by Xcode that only your machine trusts, but as far as distributing uBO in the Mac App store, that's actual money (and who knows, maybe even disallowed by Apple's policies)