Ask HN: What are similar services to ifttt?

Hi everyone! Today I made a quick task on If This Then That (ifttt), where every time a tweet is made with a certain hashtag, I tweet the username of the person who tweeted the hashtag. The problem is that with ifttt, you can't tweet at someone when using twitter as a trigger. So when someone uses the certain hashtag I'm looking for, I can't show them the link I'm trying to show them. Are there any services that allow you to tweet at someone when a certain word or hashtag is tweeted and can be found in search? Thanks!