Google Tag Manager Import Export

Google Tag Manager (GTM) is a great online tool to manage pixels and code snippets to be included on your sites. Setting up containers for different sites and copying tags, rules and macros between them however is a real pain in the ass. GTM at the moment doesn't support this, however, with a little Greasemonkey magic, everything is possible.

That is how the Google Tag Manager Import Export script was born.
If you use GTM, this will be a real life-saver for you.