Store building app

Create a Unity3D mobile app that will allow the user to build a model of a store. Screen 1 - the user builds the store structure, selecting from different building blocks - walls, windows, doors, store shelves etc. Screen 2 - the user could add products on the shelves. The products would be camera-facing textured planes. Screen 3 - The user would be able to walk through the store and look around. More details and a detailed design will be available on project acceptance and when the work starts. I'm a 3D animator and Unity programmer myself, so you can be assured that I know what you'll need in order to do this project with the best outcome.