Magnolia 5.3 reached end of life on June 30, 2017. This branch is no longer supported, see End-of-life policy.
The UI Content App module installs the Parts of a content app a specialized app type to manage custom data sets.
The UI Content App module is bundled with Magnolia and typically already installed. You can download it from our Nexus repository
Magnolia UI Content App is a Community Edition module. It is typically already installed. Launch the Configuration app and go to /modules/ui-contentapp
to check.