Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
ApproveIt for Slack - Get approvals in minutes, not days. Right from Slack!
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
AccessOwl - Discover Shadow IT, Automate Access Reviews and Auto-Provisioning — No Enterprise-Subscriptions required.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
Approve app for Zendesk - Any enforceable and auditable approval workflow for Zendesk tickets you can imagine can be easily created using the Approve app.