YouTube is apparently testing a new Smart Downloads tool that automatically downloads 20 videos a week depending on your viewing habits. Only Wi-Fi will be used to download material from the app. In order to conserve mobile data while watching your preferred channels while on the go, you must use this application.
Only Premium subscribers in Europe have access to the new function. You can enable it through Settings > Try new features > Try it out.
Prior to February 14, you must sign up to participate in the testing phase.
As soon as you run out of storage, the app will alert you to that fact and you’ll be able to access all of your previously downloaded videos by going to the Library page.