I made a Safari extension (iOS/Mac) that highlights new comments: https://apps.apple.com/us/app/hn-comments/id1602932281 https://apps.apple.com/us/app/hn-commen

I made a Safari extension (iOS/Mac) that highlights new comments: https://apps.apple.com/us/app/hn-comments/id1602932281 https://apps.apple.com/us/app/hn-comments/id1602932281 It's for new comments in general though, not exactly what you're asking. Not much interest so far. Maybe the price is too high? Since I made it primarily for myself there's at least one happy user.