Need an app developed

I have an Excel Spreadsheet that I would like to turn into a more attractive, mobile application. It is being made for lawn care companies to manage their inventory and know what products to order and if they need to order it. The concept: The user would start by "creating" their own product, setting the unit of measure (for example [login to view URL]) for that product, and add it to their saved list of products. They would have a space to enter the amount of square footage that needs to be treated (for example: 25 acres). On their product list page, they would be able to enter the quantity of each product they have on hand, and the app would compare that to the amount needed to cover the square footage they entered. It would show the user if they need to order more product and how much. If they have enough, it will show how much extra they have and will be colored green. If they need more product, they would see the amount needed and it would show in red. I would also like to have the option to override the square footage for individual products in their settings. This would allow them to enter a specific quantity that they would like to keep on hand, and the calculator would compare to that number instead for that individual product. I can handle the math side of things if need-be and have the spreadsheet as a working/functional “prototype” for you to get an idea of what I’m looking for.