An app map is a complete set of screens/pages of an application and how they are linked to each other. It establishes the relationship between among various parts/ screens of the app often represented as an interwoven web of wireframes. It helps
a. Product managers to track progress and feature completion.
b. Development teams to estimate dev effort.
c. Design teams to start putting visual layers screen by screen.
d. Business to get a 360 degree product view.