With an app defined in an XML file, navigate to Administration -> Apps to install the application by clicking on 'Add Application'
Specifing the XML file in the Source URL path press 'Load' for the application definition to be loaded, prased and the XML will be verified. Lastly, enter the secret App Key as well as specify as username and password for the application's API access to Mambu.
Pressing Save will refresh the view and save the App. It can disabled or uninstalled from the Actions Menu in the Apps Admin view.