Mmmmm....can't wait for a 7 minute battery life and 20 hr renders!
But, even looking beyond the fact that this app simply would not be possible
(due to lack of processor speed, disk space, RAM, peripherals, adequate control system, screen size, battery life, etc), why would you ever want to do this on a phone? When do you ever need "effects-on-the-go"? And the app would cost hundreds of dollars. And how do you capture to the iPhone? How do you control the precise effects? Why bother on a 4 inch screen? How do you deal with even lightly compressed Standard Def video, let alone uncompressed SD and HD? And.....and......I could go on, but there is so much wrong with this idea, that its not even worth it. Sorry.
I do suppose that WPD Lab could be ported to iPhone - there's a project for the FXhome team! After making Visionlab a Universal Binary, of course!