A vim plugin that shows changes since last git commit

I discovered this rather lovely plugin for vim, that shows a column of symbols indicating where lines have changed, been added, or been deleted, since your last git commit: https://github.com/airblade/vim-gitgutter.

I'm finding it invaluable for quickly isolating new bugs or regressions when they're in new code, without having to do a 'git diff' by hand.

To install it, I downloaded the git repo as a .zip, and copied the plugin/gitgutter.vim file to my local vim 'plugin' folder.