Write an iPhone/iPad application for online videos

The objective of the application is to deliver videos to the users via an application on iPhone and iPad. The users will use their personal devices, and for a given amount of money, via in-app purchase, they will gain access to the videos. We want the app to be generic so that we can adapt it at the very last moment for a given type of application. Example: tutorials about yoga, tutorials about cooking. The application dialogs with a web server that is already developed. Here is a list of features: they are detailed in attachment. The user downloads the application from the App Store, on his iPhone and his iPad free of charge. The user browses the catalog of videos. The catalog is fetched from our web server. The user downloads a few videos that are free. This is done in background: the user can still use the application at the same time. The user plays the videos in full screen with the standard video viewer: it supports play, pause, rewind, forward, changing the volume, using the headset, etc. The user purchases additional videos. Sometimes they should be purchased one by one, sometimes, they are available chapter by chapter (ie they are grouped together) The user clears the videos he downloaded when he wants to save space. He can download them again with no additional fees. The price will be dynamically adjustable with Apple servers without releasing a new version of the application. The features are described in * Functional description: overview of the app * Video app stories: the user stories, with many Conditions Of Satisfaction (COS). Please pay attention to the COS: they give details and we expect them to be fulfilled. * Technical description: interactions with the external components - the web server and Apple servers for in-app purchase. = Technical constraints: Programming language and API to use : Cocoa APIs using the Objective-C programming language Code quality specification : • No leak : code must be profiled and memory leak detected and fixed • No warnings : compiler warnings must be detected and fixed • Unit tested functions (except UI) : logic functions must be tested by writing relevant unit tests (UI is not required to be unit tested) • Commented : methods implementation, whenever possible must contain comments to describe the implementation logic • Documented : class, methods must be documented. Documentation must be provided describing the general structure of the code and purpose of the classes, their interactions and libraries/framework dependencies. • Modular : The code must be written in a module and reusable way • Coding rules : Class, methods and variable names must be self explanatory. Copy paste of code must be avoided->code must be factored. Code must be readable -> align parentheses, braces, etc. Variable must be explicitly initialized with default values. Variables and objects must be declared at the beginning of methods. UI guidelines to follow : iPhone OS user interface design guidelines must be complied with. = In scope: Develop the application The application should run on all iPhones since iPhone 4S (iPhone 4S, iPhone 5, iPhone 5S, iPhone 6, iPhone 6 plus). All iPads since iPad 2 (iPad 2, iPad 3, iPad 4, iPad Air, iPad Air 2, iPad mini, iPad mini 2, iPad min 3). iOS7 and iOS8 shall be supported Test all the features, including in hard conditions like low network coverage, low storage space, rebooting the phone because of low battery, etc. The application shall be tested with the web server available at [login to view URL] Although the web server is finished, we have some flexibility and we can update it. = Out of scope: The web server is already developed Design of the icons