Transferred to https://github.com/mozilla/code-coverage.
This is a simple JavaScript application displaying information from the Mozilla code coverage backend (hosted as https://coverage.moz.tools)
You can use it right now from mozilla.github.io/code-coverage-reports
You can browse the aggregated code coverage data for mozilla-central, per directory, then view file coverage in detail.
We've also developed a page to easily browse the directories & files with no coverage: these files are interesting because they can sometimes be removed altogether from mozilla-central...