I have made a browser extension that notifies if there are any changes in the ranklist of an ongoing contest.
In any ongoing contest, all you have to do is open the ranklist in a new tab. The extension will automatically refresh the ranklist page periodically and notify if any change occured.
The extension is available on firefox: https://addons.mozilla.org/en-US/firefox/addon/rank_shout/
GitHub repository: https://github.com/gkrishnan724/Rank-Shout
Feel free to report any bugs or issues.
Thanks and Happy coding!