Reddit Watch is a free tool for monitoring Reddit for posts containing certain keyword(s) in near real-time.
I built a limited version of this application for my own personal use some time ago, but I have now opened it up for anyone to use within reasonable limits.
One use of this is to filter down Reddit discussions to a few specific topics that you are interested in.
Another potentially effective use of this is for influencing Reddit discussions in a certain way.
By upvoting or commenting on certain threads as soon as they are posted, you have a much better chance for those threads to do well - especially if you have enough people participating in this. In Reddit's algorithm, earlier votes are worth more, and that is because early and positive "upvote momentum" is rewarded more. Same with downvotes. That is why downvoting a post that's already at the top of a particular subreddit will have little effect, where as downvoting a post that just got posted will mean a lot more.
It works the same with comments where commenting on a thread that already has hundreds of comments makes it very unlikely that your comment will gather enough momentum to move to the top or be seen by a great number of people.
We use the main api.proxynova.com endpoint. Go to main ProxyNova website for documentation. The old API that was previously hosted on api.unblockvideos.com will be retiring soon.