If your app is only as complex as what it appears from the website, I imagine it wouldn't be too hard to build multiple apps to do that. From your description I

If your app is only as complex as what it appears from the website, I imagine it wouldn't be too hard to build multiple apps to do that. From your description I was imagining some kind of nonlinear editor but it seems to be more constrained in functionality. Might want to do some investigation on your web analytics to see what percentage of your uses are on mac if you're looking to have some justification for making a mac native app.