Are Apps the Best Model?

Recently had a conversation with a colleague about writing an App for the IPhone for a supply chain problem. We were struck by the fact that it would have to be re-written and supported for two other mobile platforms for maximum coverage. Now that wasn't the original model for 'run anywhere' software. So what happened? Proprietary App stores are popping up all over the place, so the App store model is still exploding. Are we moving back to centralized computing? Nick Carr discusses this in Roughtype: Everybody's Appy Nowadays.