Title: Theory / Important / CS / Programming / Objective-C / Library / UIKit / System icon
On every note of this deck, unless a note says otherwise:
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/system-icons/

Name: App icon
Definition: The image shown on play store and home screen to represents the app and allow to open it
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS interface

Question: How many element should be in an icon
Answer: Only one, that captures the essence of the app
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS interface

Question: What should be an App Icon background
Answer: Opaque, simple
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS interface

Question: Can App Icon use text
Answer: No, it may be hard to read. Or only logo
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: Can App Icon use picture
Answer: No, details are hard to see in icon
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: Can App Icon use screenshot
Answer: No, too complex for an app icon and don’t generally help communicate your app’s purpose.
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: Can App Icon use interface element
Answer: No, because an element should have a single behavior when used. And the behavior can't be both "open the app" and "do something in the app"
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: Can App Icon use hardware product
Answer: No. They are copyrighted. And they change often, meaning the icon will quickly appear old
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: Can App Icon be used in the UI
Answer: No, because an element should have a single behavior when used. And the behavior can't be both "open the app" and "do something in the app"
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: What should icon be
Answer: Simple
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon
Answer2: Have a single focus point
Answer3: Be recognizable

Question: How to check the quality of an app icon
Answer: Check on backgrounds of very different colours
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: How many icons can an app have?
Answer: A finite number, provided in the app package
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: Who can change an app icon
Answer: The user only, using iOS system, not within the app
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/
Context: iOS Icon

Question: When can you use a custom-icon in your app
Answer: When system icons are not sufficient for your purpose
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/system-icons/
Context: iOS Icon

Question: What to do with system icons in your app
Answer: Add text labels
Page: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/system-icons/
Context: iOS Icon
Answer2: use them for their intended purpose only

Name: Action (share)
Definition: Shows a modal view containing share extensions, action extensions, and tasks, such as Copy, Favorite, or Find, that are useful in the current context
Context: iOS Icon

Name: Add
Definition: Creates a new item
Context: iOS System Icon

Name: Bookmarks
Definition: Shows app-specific bookmarks.
Context: iOS System Icon

Name: Camera
Definition: Takes a photo or video, or shows the Photo Library.
Context: iOS System Icon

Definition: Closes the current view or ends edit mode without saving changes.
Context: iOS System Icon
Notation: Button "cancel"

Definition: Saves the state and closes the current view, or exits edit mode.
Context: iOS System Icon
Notation: Button "Done"

Definition: Enters edit mode in the current context.
Context: iOS System Icon
Notation: Button "Edit"

Definition: Redoes the last action that was undone.
Context: iOS System Icon
Notation: Button "Redo"

Definition: Saves the current state.
Context: iOS System Icon
Notation: Button "Save"

Definition: Undoes the last action.
Context: iOS System Icon
Notation: Button "Undo"

Name: Compose
Definition: Opens a new view in edit mode.
Context: iOS System Icon

Name: Fast forward
Definition: Fast-forwards through media playback or slides.
Context: iOS System Icon

Name: Organize
Definition: Moves an item to a new destination, such as a folder.
Context: iOS System Icon

Name: Pause
Definition: Pauses media playback or slides. Always store the current location when pausing, so playback can resume later.
Context: iOS System Icon

Name: Play
Definition: Begins or resumes media playback or slides.
Context: iOS System Icon

Name: Refresh
Definition: Refreshes content. Use this icon sparingly, as your app should refresh content automatically whenever possible.
Context: iOS System Icon

Name: Reply
Definition: Sends or routes an item to another person or location.
Context: iOS System Icon

Name: Rewind
Definition: Moves backwards through media playback or slides.
Context: iOS System Icon

Name: Search
Definition: Displays a search field.
Context: iOS System Icon

Name: Stop
Definition: Stops media playback or slides.
Context: iOS System Icon

Name: Trash
Definition: Deletes the current or selected item.
Context: iOS System Icon

Name: Contact
Definition: Shows the person’s contacts.
Context: iOS System Icon

Name: Downloads
Definition: Shows active or recent downloads.
Context: iOS System Icon

Name: Favorites
Definition: Shows the person’s favorite/featured items.
Context: iOS System Icon
Name2: Featured

Name: History
Definition: Shows recent actions or activity.
Context: iOS System Icon

Name: More
Definition: Shows additional tab bar items.
Context: iOS System Icon

Name: Most Viewed
Definition: Shows the most popular items.
Context: iOS System Icon

Name: Most recent
Definition: Shows content or items recently accessed within a specific period of time.
Context: iOS System Icon

Name: Search
Definition: Enters a search mode.
Context: iOS System Icon

Name: Top Rated
Definition: Shows the highest-rated items.
Context: iOS System Icon

Name: Alarm
Definition: Sets or displays an alarm.
Context: iOS System Icon

Name: Audio
Definition: Denotes or adjusts audio.
Context: iOS System Icon

Name: Capture photo
Definition: Captures a photo.
Context: iOS System Icon

Name: Capture video
Definition: Captures a video.
Context: iOS System Icon

Name: Cloud
Definition: Denotes, displays, or initiates a cloud-based service.
Context: iOS System Icon

Name: Confirmation
Definition: Denotes that an action is complete.
Context: iOS System Icon

Name: Date
Definition: Displays a calendar or event, or performs a related action.
Context: iOS System Icon

Name: Home
Definition: Indicates or displays a home screen. Indicates, displays, or routes to a physical home.
Context: iOS System Icon

Name: Invitation
Definition: Denotes or displays an invitation.
Context: iOS System Icon

Name: Location
Definition: Denotes the concept of location or accesses the current geographic location.
Context: iOS System Icon

Name: Love
Definition: Denotes or marks an item as loved
Context: iOS System Icon

Name: Mail
Definition: Create a mail message
Context: iOS System Icon

Name: Mark location
Definition: Denotes, displays or saves a geographic location
Context: iOS System Icon

Name: Message
Definition: Creates a new message or denotes the use of messaging
Context: iOS System Icon

Name: Prohibit
Definition: Denotes that something is disallowed.
Context: iOS System Icon

Name: Shuffle
Definition: Inidacets or initiates shuffle mode
Context: iOS System Icon

Name: Task
Definition: Denotes an uncompleted task or marks a task as complete
Context: iOS System Icon

Name: Task completed
Definition: Denotes a completed task or marks a task as not completed
Context: iOS System Icon

Name: Time
Definition: Denotes or displays a clock or timer
Context: iOS System Icon

Name: Update
Definition: Updates content
Context: iOS System Icon