Guard::BowerRails automatically install/update your bower dependencies when needed

Guard::Busted automatically run your specs

Automatic folder clean up with Catalog.

Guard::Cedar automatically runs your Cedar suite.

Guard::Chef allows to automatically & intelligently update roles, cookbooks, and databags for chef.

guard gem for clockwork

Guard::Cloudformation automatically validates cloud formation templates.

A guard plugin for CocoaPods.

Guard gem for codeception

Guard::Codespell uses codespell to automatically look for typos in your codebase.

Guard::CoffeeDripper automatically generates your coffescript from your parts of coffee

Guard::Cogs packages your coffeescript, javascript, sass, and css.

Guard::Combustion automatically restarts Combustion when watched files are modified.

Guard::ConcatFilter automatically concatenates files in one when watched files are modified.

Guard::Cookstyle automatically checks Ruby code style with Cookstyle when files are modified.

A Guard plugin to watch and copy files

Guard::CtagsComposer uses ctags utility and generates 2 files: tags -- with tags generated from project's source tree and vendor.tags -- with tags generated from vendor folder.

Guard Cunit should automatically build your C project and run CUnit based tests

GuarDb: is a guard extension handling the rake db:clone:test when schema.rb changes

A short summary, because Rubygems requires one.