• Core Services: the Core Foundation and the Foundation Framework are found by the developers here which are basic system services. This layer also supports features such as location and networking services. • Cocoa Touch: hold up the basic app infrastructure and delivers key application frameworks such as, multitasking, touch-based input and push notifications. • Media: enables the app to deliver audio, video and graphic capabilities.
Integrated Development Environment (IDE) – Xcode
The most ideal IDE to construct iOS applications is Xcode. Apple’s Xcode IDE is the most productive and holistic iOS application and comprises the core of tasks involved in app development. Xcode is only compatible with OS X Yosemite or later and needs a Mac to use it. The Xcode can be used to design, develop and debug apps on iOS platform. It has features useful for editors to work with the code, engage using interface elements and most importantly use templates for developing various other apps. Xcode has powerful features such as iOS simulator which give you a look and feel of the app on different devices, the automatic layout that automatically adapts screen sizes to different devices and storyboards that give physical representations of related objects and their hierarchy. The Xcode also requires a language such as Objective C and swift to carry out development. Objective C is found to be reliable whereas swift being newly introduced is found to be easy to learn and design with, at the same time.
Application bundle – iOS
A bundle is a file directory with a defined structure and file extension. Application bundles are directory hierarchies. The core of this bundle is comprised of the compiled code in the form of an app executable file. The bundle includes property list file , custom files, localized resource files placed in their own language-specific sub-directories.
UI/UX Design
The UI and UX Design should cater to the current market needs of the customer. For example, if the customer is looking for a simple look and feel as opposed to unnecessary complexity in the UI then the design must be prioritized accordingly. It is always good to decide on optimal text size in the app since excessive size leads to more scrolling, and if the text is illegibly small it leads to loss of time in zooming in parts of the app for clarity. Every task performed must have the minimum number of steps logically required to arrive at the end result. Touch functions are another major priority. For example, the duration of touch that is used as a variation for different touch functions.
Testing
One of the most vital steps in developing an iOS app is the testing phase wherein the app is released to a fixed group of developers who test out the app- this is called the alpha review. The next step is to release the app on a trial basis to its customers so that any bug fixes required can be incorporated based on user feedback- this is called the beta review. While testing the app, X code IDE is equipped with a debugger which can be used in locating issues in the code by inspecting the data structures and the control flow. This data is then later used to rewrite the code as required.
