AWS AppConfig is now available in the AWS GovCloud (US) Regions. AWS AppConfig helps you deploy application configurations in a managed and monitored way just like you do with code deployments, but without the need to change the code if a configuration value changes. AWS AppConfig is intended for users who want to quickly and safely deploy changes that are used during runtime of an application or platform. AWS AppConfig is a feature of AWS Systems Manager, which helps you to automate operational tasks across your AWS resources.
Source:: Amazon AWS