How to integrate Microsoft Bing Map Navigation functionality to iPhone application?

this project might be a good starting point for what you are looking for: https://github.com/route-me/route-me

You cannot create a turn-by-turn navigation product using the Bing Maps (or Google Maps) SDK. You can use it to generate directions but cannot present any sort of alert for upcoming turns. From the TOU at http://www.microsoft.com/maps/product/terms.html:

Restrictions on your use: We do have some restrictions on your use of the service. You may not:

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present or alert an end user to individual maneuvers of a route in any way that is synchronized with the end-user’s sensor-based position along the route, (e.g. “real-time” navigation);

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