Mobile Costing Application

I would like to have an app developed that would allow the users to quickly input some details into fields that would allow them to know what they should charge for a job or a project to be profitable relative to their costs. The data that calculates the figures will be intellectual property on my end but for my formula's to work, I need to have some information from the client thus the client will have to answer some questions that will allow me to take the answers and populate into my costing structure. This would mean every client would need their own account as every person's answers will be unique as well as their businesses. Simple example; Business: Laser cutting Material fee: $250 (prices received from customer) Machine depreciation: $2250 (received from customer) Rent: $500 (received from customer) Labour: $80000 (received from customer) Labour Allocation %: 100% (adjusted by client using protected formula) Cost price: $452.79 (projected using protected formula) Margin %: 100% (projected using protected formula - client can adjust % values to get within a price point which they think is more applicable to the project) Selling price: $908.58 (projected using protected formula) Gross profit: 50% Later development of the app would allow the quoted amount reflected in the selling price to be sent as a PDF quote to the both the customer and their intended customer for which the project is intended. I would need a means to input values into the application from my laptop that would allow me to develop the costing of the new customer on Excel. After I have it, I would need to be able to only input some figures into the app that is not visible to the customer which will allow their input figures to work with my formulas to give them the costing value that they are looking for to quote their customers. The application needs to be a subscription model.