In an Azure Websites I was always using the following code to fetch some values from the config\'s app settings:
string property = WebConfigurationManager.
WebConfigurationManager and CloudConfigurationManager manage different configuration files.
WebConfigurationManager is for managing website's web.config file(s) and it's appsettings and connections strings
CloudConfigurationManager is for managing .cscfg files (for cloud services). His benefit is that you can manage configurations and connections from the azure portal directly.