Librus Average by Krzysztof Zdulski

NEW: Clear the clutter! Now you can hide subjects that you do not have any grades from. Just enable it in the options menu in the browser toolbar.

This extension allows you to show the average on Librus Synergia's website. Some schools decide to hide the average from you, that's when this extension comes in. It is highly customizable when it comes to calculations. The extension is fully open source and you can check it out on GitHub: https://github.com/librus-stats/librus-average.

Also available in Chrome Web Store:
https://chrome.google.com/webstore/detail/librus-average/meankokoepgpipcnhcckojgcnkpnagng?utm_source=firefox&utm_medium=store_page
And for Opera:
https://addons.opera.com/en/extensions/details/librus-average/