Startup Idea : Work GPS

How many of us working in offices tend to miss or go late to meetings because we cannot find our way easily especially when you are new at work? What if its a big corporate office that has too many buildings and there is no directory giving you step by step directions? What if there was a GPS just meant for work locations? This means the geo locations have to pre-defined for the rooms and we need to find directions from our own geo location through phone. Not sure if this is feasible. Ideas/inputs welcome.