Basic Plugin for integrating Kongregate's Leaderboard. This plugin supports C2 and C3 runtimes so you can add it to any of your projects. Check out my other HTM...
I haven't made a tutorial but is fairly easy following Kongregate's instructions:
docs.kongregate.com/docs/concepts-statistics
Then use the action "Submit Score" passing the leaderboard name as a string and the score you want to post. As simple as those two steps are.
docs.kongregate.com/v1.0/reference
If you need more information, you can open a thread on the forum and tag me in to help you up.