iOS

It does! AirDrop in iOS 7 lets you exchange files like pictures, Passbook passes, and contacts between two iOS users over Wi-Fi or Bluetooth, without any configuration and (as Apple’s Craig Federighi pointed out) without the need to walk around and “bump” phones with people. AirDrop appears in the Share sheet, along with more conventional items like Mail and Messages; you can even use it to share multiple items to multiple people at once. Files end up right in the appropriate app and are encrypted during transmission. You can also change permissions to determine whether everybody can share with you, or only certain people nearby (or people in your contacts).

When you build your iOS app, Xcode packages it as a bundle. A bundle is a directory in the file system that groups related resources together in one place. An iOS app bundle contains the app executable file and supporting resource files such as app icons, image files, and localized content.

Fast enumeration is a language feature that allows you to enumerate over the contents of a collection. (Your code will also run faster because the internal implementation reduces message send overhead and increases pipe-lining potential.)

A special C data type that encapsulates other pieces of data into a single cohesive unit. Like an object, but built into C.

NSArrayʼs contents can not be modified once itʼs been created whereas a NSMutableArray can be modified as needed, i.e items can be added/removed from it.

Retain counts are the way in which memory is managed in Objective-C. When you create an object, it has a retain count of 1. When you send an object a retain message, its retain count is incremented by 1. When you send an object a release message, its retain count is decremented by 1. When you send an object a auto-release message, its retain count is decremented by 1 at some stage in the future. If an objectʼs retain count is reduced to 0, it is deallocated.

No, the delegate is never retained! Ever!

The frame of a view is the rectangle, expressed as a location (x,y) and size (width,height) relative to the super-view it is contained within. The bounds of a view is the rectangle, expressed as a location (x,y) and size (width,height) relative to its own coordinate system (0,0).

The app has not been launched or was running but was terminated by the system.

The app is running in the foreground but is currently not receiving events. (It may be executing other code though.) An app usually stays in this state only briefly as it transitions to a different state. The only time it stays inactive for any period of time is when the user locks the screen or the system prompts the user to respond to some event, such as an incoming phone call or SMS message.

The app is running in the foreground and is receiving events. This is the normal mode for foreground apps.

The App works with any device that is running iOS version 7 or greater.

The app is in the background and executing code. Most apps enter this state briefly on their way to being suspended. However, an app that requests extra execution time may remain in this state for a period of time. In addition, an app being launched directly into the background enters this state instead of the inactive state. For information about how to execute code while in the background, see "Background Execution and Multitasking.

The app is in the background but is not executing code. The system moves apps to this state automatically and does not notify them before doing so. While suspended, an app remains in memory but does not execute any code. When a low-memory condition occurs, the system may purge suspended apps without notice to make more space for the foreground app.

Signing an application allows the system to identify who signed the application and to verify that the application has not been modified since it was signed. Signing is a requirement for submitting to the App Store (both for iOS and Mac apps). OS X and iOS verify the signature of applications downloaded from the App Store to ensure that they they do not run applications with invalid signatures. This lets users trust that the application was signed by an Apple source and hasn't been modified since it was signed.

You can switch it off easily: Settings>General>Keyboard and toggle that switch to Off.

Layer objects are data objects which represent visual content. Layer objects are used by views to render their content. Custom layer objects can also be added to the interface to implement complex animations and other types of sophisticated visual effects.

Views along with controls are used to provide visual representation of the app content. View is an object that draws content in a designated rectangular area and it responds to events within that area.

If the clicks of your iOS 8 keyboard are driving you mad, switch it off in Settings>Sounds>Keyboard Clicks, toggle to off.