I started my continuous intagration with Buddy. This is very good tool to start with. Easy configuration, many options and integrations, everything configurable via web page interface. My build proccess was configured in few minutes. Then I tried CircleCI and I like it. After you read documentation, it is easy to configure. Builds are faster. I can store/share artifacts, test result. Build wolkflow description is stored in repository. Now I prefer to use CircleCI