Let's install a YouTube download extension that will enable you to download YouTube movies. You will also learn how to install a Google Chrome extension that isn't in the Google Chrome store.
If for some reason your Android powered smartphone does not perform as good as it used to, or you want to sell it I suggest you to bring it to its original factory state.
Dropbox is an amazing cloud based web service enabling you to store your stuff like pictures and documents and access them from any device with an Internet connection. Plus you can share the stored items with others.