To be open with you, I've never done professional work in the field, but video editing has been a hobby of mine for the past 8 years. I'm not here to make money, I'm not here to whip out a half-assed video for a couple bucks, I'm here to show you what I'm capable of.
Having been an active creator, I've created several promotional videos for individual purposes, usually for classes or other independent endeavors. If you want a video to clearly, efficiently, and cleanly represent your App to thousands of eyes, I have no doubt that I can give you the quality you desire.
All you need to do is say yes, and we're ready to go.