A great third party product is PlatformManager by In4BI, a Qlik Technology partner.
This flagschip product does not only provide version control. PlatformManager simplifies your development and deployment process, saves time with in testing your apps, provides insight in relations, visualizes all QVD relations, manages your Extensions, Mashups and Widgets, Reload tasks, provides a workflow for approval and much more.
With over 150 Customer it's the most used Governance solution available today. With presence in over 19 countries you can probably find a partner nearby. You can download a demo video through PlatformManager.com.