Thanks for mentioning notify.ly, Simply, u can use notify with slack to get notifed if your name, domain, or any other topics get mentioned in key sites like HN posts and replies that how I found this reply ;)

Also we recently introduced source settings by which you can tailor your notifications for example follow a certain product on PH and so on.

We do support Twitter, tumbler, HN, PH, reddit and much more.

It's 100% free

cheers ^^

Behind the scenes it's just using the Algolia API: https://hn.algolia.com/?query=zapier