Is there an iphone app for youtube downloads?

*I can't find decent website that is suitable with Iphone and youtube downloads. If there's one instead of an app. Please write it down.

There are video downloader apps…

https://itunes.apple.com/...06548?mt=8

but they will not work with YouTube as YouTube does not allow downloading only viewing the stream from the YouTube site…

"you agree not to access Content or any reason other than your personal, non-commercial use solely as intended through and permitted by the normal functionality of the Service, and solely for Streaming. "Streaming" means a contemporaneous digital transmission of the material by YouTube via the Internet to a user operated Internet enabled device in such a manner that the data is intended for real-time viewing and not intended to be downloaded (either permanently or temporarily), copied, stored, or redistributed by the user."

http://www.youtube.com/...late=terms