Shows the perspective of one player for replays. Alt+A toggles perspective mode, Alt+S or Shift+Alt+S cycles through active colors
Here's a gif of the extension in action on a free for all replay,
This extension allows you to view a replay from the perspective of one player, without seeing all the tiles. You can toggle perspective mode by pressing Alt+A. Alt+S or Shift+Alt+S cycles through active players. These shortcuts are customizable via the chrome://extensions page, "Keyboard shortcuts" link at the bottom.
The tool is not set up to show the perspective of multiple players in team games, however, if there's interest I can add that.