At a previous job, we started using Git notes to add additional metadata to our Git commits. Atlassian Bitbucket did not show these Git notes, which made it impossible to see the notes without cloning the repository. I wrote a plug-in to add a column to the commits view to lower the threshold to view the notes.
You can find the plug-in on my Github here: https://github.com/daveychu/git-notes-plugin
At my current job, we use Hippo CMS as our CMS of choice. It is a Java-driven application which uses a tree of nodes as its data model. The Hippo CMS console is a feature that allows developers and maintainers to see and modify this data structure on a low level. However, once the tree of nodes gets sufficiently large, the console does not keep the master view in sync with the detail. I wrote a plug-in for chrome that simulates this synchronization. You can find it in the Chrome store here: https://chrome.google.com/webstore/detail/hippo-cms-console-helper/cfgilafjddciddcepdaaglgcggfpaepi
The small amount of code powering the plug-in can be found on my Github: https://github.com/daveychu/hippo-cms-console-helper.