diff --git a/README.md b/README.md
index c8eac0a..3f3291c 100644
--- a/README.md
+++ b/README.md
@@ -601,6 +601,7 @@ Services to securely store your Docker images.
 - [DockerSpec](https://github.com/zuazo/dockerspec) - A small Ruby Gem to run RSpec and Serverspec, Infrataster and Capybara tests against Dockerfiles or Docker images easily. By [@zuazo](https://github.com/zuazo)
 - [Dockunit](https://github.com/dockunit/platform) :skull: - Docker based integration tests. A simple Node based utility for running Docker based unit tests. By [@dockunit](https://github.com/dockunit)
 - [InSpec][inspec] - InSpec is an open-source testing framework for infrastructure with a human- and machine-readable language for specifying compliance, security and policy requirements. By [@chef](https://github.com/chef)
+- [Pull Dog](https://github.com/apps/pull-dog) - A GitHub app that automatically creates Docker-based test environments for your pull requests, from your docker-compose files. Not open source.
 - [Pumba](https://github.com/alexei-led/pumba) - Chaos testing tool for Docker. Can be deployed on kubernetes and CoreOS cluster. By [@alexei-led](https://github.com/alexei-led)
 
 ### Wrappers