In that case you can use a simple front-end solution, like
Android: Tubemate
Windows+Linux:Youtube-DL-PyTK
I really recommend you get used to youtube-dl on command line though, it's the best way to exploit the tech with precision, for e.g. if you want to download an entire TV series you can set a macro to give each file a nice name and select which video/audio format to use, etc.
well he can use Tubemate which is a nice front end for Youtube-DL. I have downloaded Youtube, Dailymotion, Camwhores , Pornhub , Openload on Tubemate
Actually It's available on Amazon Prime Video, but you have to set your location to USA or have a American prime account.
And it's actually free with Prime! I could have recorded it for everyone but din wanna commit copyright infringement lol
Since there was 3 requests for this.
Get Premier Clip for mobile:
I've used that famous Jessica Biel clip with Adam Sandler from Now Pronounce You Chuck And Larry. Because Adam Sandler's face interrupts twice. Basically the clip above gets rid of his face creating a seemless view of Jessica Biel.
Remember iOS has it's limitation of file types (MP4 preferred)
I primarily use a PC with Adobe Premier Pro and Sony Vegas.