iphone app demo

I am looking to hire someone with expertise in mobile app design to create an app demo that is more than two minutes in length. The intended purpose of this app demo is to promote an iPhone app, so it should be clear that the primary platform is iOS; the app is in the making and not ready as of now. I am looking for someone who can create an effective demo that effectively showcases the features and usability of the app, thus allowing me to reach a larger, more engaged audience. Please let me know if this kind of project is something that you could do for me. The main scope of this job is to design and execute a DEMO for an iPhone app. Thank you!