Can be built as web app (browser based) or iOS/Android app - whatever is more affordable.
The tool will be used by roofing cost estimators to present to a potential customer. Customer will make inputs into the tool (type of roof, roof size, color, options) based on their desired product, and the tool will calculate a cost estimate at completion of all inputs and display itemized breakdown of costs on a final page. The interface should be attractive as the customer will be using it directly.
I have attached a detailed description of the project including an Excel Spreadsheet which will serve as the framework of the app (scope of work and logic).