You can download videos from Youku using android app 'Videoder'. Videoder is an android apps that lets you download videos and music from Youtube, Facebook, Instagram, Youku, Voot and many other sites.
Open Youku website and search for the video that you want to download and open the one you want to download.
When you tap on a video a red download bubble appears on the left bottom corner of your screen. Tap on the download bubble to view the download links and choose the video quality in which you want to download.
You can then choose the resolution in which you want to download the videos and start your downloads.
Once resolution is selected a dialog appears which allos dyou to select your download location and start your download.
You can tap on the download icon on the top of the screen to view your downloads. Or you can check them in the notification panel.
We just say you to try it once. Its free. And we bet you won't regret your decision.