Cellphone GPS that will allow you to get to your class at George Mason University

Write a description of an app. for cellphone GPS that will allow you to get to your class at George Mason University (with directions) and an explanation of why the system is the most appropriate solution compared to alternatives. This GPS application will allow you to get 3 metres close to the classroom, because inside each building the GPS service/network gets lower.therefore once destination is reached, a pre-recorded video of each classroom door will pop-up with perfect directions that will allow you to find the right classroom. 550 words or more if you could for same price.