There are lots of different kinds available. Some cost money, some are built into Learning Management Systems like Moodle and Blackboard, some can be built into things like WordPress, Drupal and other Content Management Systems. Most teachers don’t have access to these things, and at my university there’s currently no way to implement a leaderboard using our Moodle system. We can however ‘fake’ it by using Google sheets and embed that sheet in our Moodle using the HTML block on the side of the Moodle class page, or by creating a blank webpage and embedding your file in the Moodle.
This web page explains how to embed and publish a specific range of cells of Google sheets in your webpage.
Finally, you could also maintain an excel spreadsheet just as easily, but remember you will have to constantly upload and replace your previous sheets. Time consuming, but worthwhile. Students love getting points.
Take a look below. You can get very fancy with your leaderboards. The horserace below was made using google sheets as well.