There are three different ways to select the videos you want included in your app.
From the Video Type drop-down menu, you can choose "URL", "Channel" or "Search". Then, depending on which one you chose, in the field below enter the sharing URL of a single video on YouTube (e.g. http://www.youtube.com/watch?v=J4atfEFCS7o). Or a YouTube user’s Channel Name, like “InfiniteMonkeysLLC”. Or Search terms like “funny pranks”. Remember, you need to make sure the Video Type matches the type of data you enter – URL or Channel or Search. When you’re finished, just click Save. You can use the Preview in The Machine to make sure that your selection works.