YouTube is a well-known video sharing website that provides you with countless software tutorials, documentaries, music clips, and many other. iTubeDownloader is a Mac application that offers you an easy and quick way to watch and download the aforementioned videos for offline playback.
The program comes with an integrated browser where you can log in to your YouTube account, search uploaded videos, watch music clips, create playlists, etc. Basically, you can accomplish any task that can be completed on YouTube with your default browser.
In addition, the application can automatically retry failed downloads. You just need to enable this option from the Preferences menu -> Advanced.
Personally, I wouldn't choose this app for YouTube video download. I say this mostly because it supports only one output format (MP4) and it doesn't offer you any common output settings (like select proper bitrate, video codec or frame rate).
As a conclusion, I'd suggest you to try other programs when you wish to download YouTube video clips. There are many similar applications that bring an integrated video converter and offer support for more than just one output format. What's more, they come without a price tag, so it's not exactly worth installing and using iTubeDownloader on your Mac PC.