Native app is waste of money and energy.
Responsive is good enough. Write small app that would only create Desktop Shortcut and icon and assist with registration process. Firts block on web page can be designed to look like native app...
Yes, my general point is that native app is a good thing, but it's only viable at the stage when, say, 10% of the community using the app would make a difference for your strategy. In the beginning, and for the overall site - responsive is the way.
