There will surely be times when you really like a video on YouTube and like to save it on your iPhone or iPod Touch. Apple by default do not provide that feature, neither do they allow any app which can do that for you. Jailbreaking an iPhone or iPod Touch has its own advantages and increases the potential and possibilities of the device much beyond what Apple intends. The YourTube app lets you download Youtube videos directly from the native YouTube client, but then it is not Free.
Well, now there is a free alternative for YourTube, called WatchMob which is available in Cydia under BigBoss and Planet iPhones repositories. This free application gets added to you springboard and allows you to search YouTube for videos and download them.
The application lets you search for the videos and even lists all the previously downloaded videos neatly and allows them to be played back. Videos downloaded with WatchMob will not show up under your device’s native library, and can only be played through the application itself.