If we develop a mobile app from scratch, we check the app idea and finalize the entire features of the app first. Based on that, we make wireframe and show the client. If client approves it, we make a final UI/UX design of the app with high quality resolution. We build backend apis first and after that, develop mobile app front end and integrate with backend apis to complete the app. Normally we launch the MVP version first if the client is fine, and add more features and fix issues to grow up more.