How much does it cost to build an app. Let’s break it down To build an app you need team of a frontend developer, a backend developer, designer, project manager and QA specialist. For a small to medium sized project you need around 80hours of design, 120 hours for frontend and 180 hours for backend, 80 for Project management and QA. This approximates to 450 hours of development Cost per hour ranges from $10 - $100 depending on teams/ individual experience and location.