This chapter has introduced the software and hardware that we will use to make computer vision applications for iOS. We set up a development environment, including Xcode, the iOS SDK, the Xcode Command Line Tools, a prebuilt version of OpenCV's standard modules, and optionally a custom-built version of OpenCV's extra modules. Using these tools and libraries, we developed an iOS application that performs a basic image processing function and we built it for iOS simulators and local devices. We discussed some of the places where we can seek more information about Apple's app distribution process, the iOS SDK, and OpenCV. Finally, we compared the camera specifications of iOS devices and learned about accessories that may help us capture clearer and more specialized images. The next chapter delves deeper into the topics of computational photography and image processing as we will build an application that can capture, edit, and share photographs.