There's a version of track changes available in "compare" mode (see https://www.writelatex.com/blog/154-a-first-look-at-the-new-version-comparison-feature https

There's a version of track changes available in "compare" mode (see https://www.writelatex.com/blog/154-a-first-look-at-the-new-version-comparison-feature https://www.writelatex.com/blog/154-a-first-look-at-the-new-... for details), and we'll be releasing a further update to this in the near future.