BusBus NYC is a free iPhone app developed by MGS Technologies LLC. It falls under the Travel & Navigation category and allows users to track MTA buses in real-time. With this app, you can easily find out where your bus is located and plan your journey accordingly.

Currently, the app provides real-time tracking for a limited number of buses. However, the MTA is working on expanding this service to cover more buses in the future. It's important to note that the limited availability of buses on the app is not a limitation imposed by BusBus NYC, but rather a result of the MTA's gradual rollout of live data for all bus lines.

If you're a frequent bus commuter in NYC and want to stay updated on the whereabouts of your bus, BusBus NYC can be a useful tool. Keep in mind that the app does not cover all MTA buses at the moment, but it's a promising step towards providing real-time bus tracking for a wider range of routes.