Design of the app is one of the most important parts of your app success. Let’s figure out how much should it cost. Investing in high level design is the best way to convert viewers to downloads and have a growing impact on user engagement metrics. You can be sure that’s not an accident that top featured iPhone and iPad apps all have great design. So now, we have try to answer the question: how much does it cost to design an app? Or How much should designing an iPhone app cost?