Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
TeeSpring - Create & sell t-shirts you can be proud of
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
RedBubble - UNCOMMON DESIGNS BY INDEPENDENT ARTISTS EVERYWHERE
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
Merch by Amazon - Create, sell, and promote custom branded t-shirts