Hi!

This example demonstrates how separately hosted 3rd party web-apps can be seamlessly integrated into TestRail.

The plugin will recreate an “Add test case” form according to your setup and allow you to create a new test case. Since this is just a proof of concept, there's no corner case handling, only primitive validation, the code is horrid, and things may break painfully.

The plugin is hosted here (GitHub pages).
Host UI script for TestRail can be found here (Gist).
GitHub repository is here.

I don't collect any data — this page communicates with nothing but your TestRail (or at least not under my governance).