YoutubeDL-iOS is a wrapper around youtube-dl and allows you to download YouTube movies to your iOS device. Because it uses youtube-dl, it'll always try to get the best quality, and should work with most youtube movies.
This isn't distributed through the App Store, and is unlikely to get approved by Apple. So, you'll have to build it yourself and put it on your own iOS device. It should support both iPhones and iPads.
Once you have it running, press the '+' and paste in the URL of a YouTube playlist. You should then be able to download all the movies in that playlist. It doesn't support individual movies, or YouTube users yet.
Mainly because it uses youtube-dl.
Yup, it's the first time I touched Cocoa stuff since 2009 or so. Never used Swift before, and only spent a few hours on this.
Yeah, would be great to fix this. It uses Python-Apple-support, so we can possibly download a copy from github instead. I wanted to make it relatively easy to get started with this.
The official API requires an API key, and I'm a bit hesitant to use that with a project like this.
Great, I'm open to all contributions!