To the 1 star review: This add-on needs access to all websites because "this is the only extension that supports custom-hosted GitLab instances".

Why does this need access to all websites if its only for gitlab?

This is one of the features GitLab lacks, thanks for the effort bringing it. However, this addon may benefit from some improvements:
- ability to switch on/off tree view to show all changes (to be able to find something in changes via text search on page)
- tree width is fixed as I see it and when directory structure and file names are very long it becomes hard to use this tree. Should be able to resize tree area (especially when there is a lot of free space left on sides)
- clicking on file name scroll page somewhere upwards regardless what file name you click