Create a 1 minute or less App explainer promotional video

I already have HD footage of my App and someone pressing buttons and scrolling through it to highlight some of its features - this was professionally done and came as a package with some Raw footage and screen shots, etc, for ease with final production/editing. What I need now is for it to be turned into a 60 second promotional video, with animation. This would involve editing and animation skills. I have a script of no more than 150 words. It would also be nice if you could provide a British voiceover and background music.