The app will check for a new config file once a day. This quite often allows me to add support for new cameras without having to push a new version of the app through the app store. Generally you don't need to force the config but if I've just added a camera and I want you to try it out straight away, you'll want to follow these instructions:
(Note that you can use the settings within the app but you will still need to go out of the app and back in for it to pick up the config).
The only indication that the config has been updated is the spinning activity indicator in the status bar during the download. Please note that you will only need to do this once and the setting will then change to Off of 0.