There are plenty of apps supposed to help you download YouTube clips in the Windows Store, but in case you’re looking for a free one with an interesting feature package, DownTube might be the right choice.
As you could find out by simply reading its name, the purpose of the app is to help you download YouTube clips without leaving the Metro interface of your Windows 8 computer
It packs features to help you watch and download YouTube videos in either MP4 or MP3 formats, while also providing support for live tiles and the share charm.
There is no limit of concurrent downloads, while the built-in notification system alerts you whenever a new download comes to an end.
DownTube can be used on any Windows 8 computer, be it x86, x64 or ARM, and is completely freeware (a license, however, removes the in-app advertisements).
to view the official product page of DownTube in your browser.