Explaining the code in a pull request to the reviewer with a flow is hard, especially when the number files in the PR is big and flow of code execution jumps between multiple files.
With Tour my pull request you can create a tour based on your flow and get your PR merged swiftly.
Demo video:
https://chrome.google.com/webstore/detail/tour-my-pull-request/gfmcmkcdciebhnhcbchighdeegdaonnc/
This is an initial release, so please report me any issues or suggestions. I will try to address it. You can reach me on twitter @sureshdsk. If you like the idea, please spread the word with your colleagues and friends.