Reddit List - Tracking the top 5000 subreddits
Searchlight a Colleague - Searchlight helps you write powerful words of support that highlight strengths and work styles, so that your teammate isn’t just a name and resume.
Reddit Check - A tool to check if a URL is on Reddit and going viral
Peoople - Find the best recommendations
Orangered - A daily summary of your favorite subreddits
Recombee - Recommender system as a service that uses advanced Machine Learning and Artificial Intelligence algorithms. Easy to try and evaluate.