What do you have in mind for the style and theme of the app?
Please download the 'parcel track' app. Its in the US app store. Not sure about the other stores. It makes something as boring as shipping very simple to use and interesting enough to stay in.
The goal is to make the app seamless like the website or focus on whats important. The five pages (guide)
home page (sort of like a welcome page, but can be also be the login page similar to the parcel track app)
Register for free / Login
After login (I recommend signing up on gopostal.co to see the necessary info that shows up once you are logged in - use 000-0000 when asked for phone number to register)