KWatch.io - Monitor Keywords on Reddit, Twitter, Linkedin, Quora, Facebook, and Hacker News. Receive an instant alert when specific keywords appear on social media.
Groouply - Track keywords on Facebook groups
F5Bot - F5Bot will send you an email whenever your brand, product, or keyword is mentioned online.
Notikey - Get notified when your keywords are mentioned on Reddit
Syften - Better social media keyword alerts
UpvoteTracker - Track the upvote history of Reddit and HN posts