Is there one killer app for the iPhone? The cumulative experience is the killer app. Likewise, the persistent AR environment will also show us value from the collective, incremental improvements over non-augmented experiences: the sidewalk up ahead has a splash of black ice, the pollen count is high by the creek so cycle on the main road today, etc.
I’d argue that a good mobile browser was the killer app that brought the iPhone to the forefront. It differentiated it from what else was available at the time. It’s hard to pinpoint a killer app now because the ecosystem is mature, but a killer app is often what gets a platform off the ground in the first place.
