1. iPhone App Development
Overview
Brian Knittel
Brian Knittel Consulting
Software Engineering and Architectures
April 27, 2009
Please do not distribute without permission

2. Who I am
Clients: Cisco, Scientific Atlanta, MIPS, etc.

Specialties

 Mobile/Embedded: iPhone, Cable set-tops, etc.
 Video, Audio, Graphics, & Networking
 Cable TV Networks
 Architectures and Design
 Top to bottom, human interface to drivers
Currently working on my own iPhone Apps


3. Overview
Application Landscape
Crowded, varied, and wide open
Application Production
As easy as iTunes
iPhone Technologies
Objective-C
Dynamic Connectivity
Expansive and expanding Dev Env and Toolkits

4. Application Landscape - Numbers
Over 25,000 Apps

30M iPhones and iPod Touches
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Over 1 Billion downloaded Apps
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– Guess $37M from 19M Apps
Top selling Crash Bandicoot game
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– About $6M from 1M sold

5. App Categories
Books Navigation
 
Business News
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Education Photography
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Entertainment Productivity
 
Finance Reference
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Games Social Networking
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Healthcare & Fitness Sports
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Lifestyle Travel
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Medical Utilities
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Music Weather
 

6. Top 10 All Time Apps
Paid Free
Crash Bandicoot 1M Facebook
Koi Pond 944K Google Earth
Enigmo game 850K Pandora Radio
Bejeweled 2 game 815K Tap Tap Revenge
Shazam
iBeer 780K
Pac Man Lite
Moto Chaser game 745K Backgrounds
Pocket Guitar 710K Touch Hockey
Flick Fishing game 670K Labyrinth Lite
Tetris 635K Flashlite
Texas Hold'em 600K

7. Cool Apps (my opinion)
Free
Built in
 Wikipanion
 Phone/Contacts
 SnapTell
 Mail
 Translator
 iPod
 Weather Channel
 Maps  Urban Spoon
 Calendar  Mint.com
 Photos  Kindle
 Web Browser  Facebook
 Stocks  Pandora Radio
 Text (messaging)  Shazam
 Camera  Skype
 Clock (timer,  FarFinder
world, ...)  WebMD

8. Application Distribution Channel
iTunes Store – as easy as selling music

Apple takes 30%, sends you a check monthly
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 Free is free
Free to develop using the Simulator - ADC
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$99 to develop for iPhone and ship products
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My application is in progress
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 Developed in 4 months (Inc. learning curve)
 Still needs refinements, SQA

9. New for 3.0 Release in June
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Peer to Peer over Bluetooth
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Subscription and Pay for Features
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SW access to HW Plugins
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Push – Signal to Apps that are not running
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Cut, Copy, & Paste
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Spotlight Search of iPhone contents
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Voice Memos
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10. •Rumors of two new iPhones and
an iPod Touch in June
iPhone “mini”: $99-$149
no wireless, 4 or 8 GB, 2 MP camera, slimmer
iPhone “3G+”: $199
2x speed 3G (7.2Mbs) and wireless 802.11n
3.2 MP camera, video recording, compass
Faster CPU, 32 GB option, (256 MB memory?)
iPod Touch “3” – Add some iPhone capabilities?
Bluetooth? Camera? Microphone?

11. iPhone Technologies – Objective C
Objective C (similar to C#)

Based on Small talk, developed in early 80's
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Goal: Simple Object Oriented Coding
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Strict superset of C, mix with C or C++
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Polymorphic, Single Inheritance, no Templates
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Dynamic Typing, Binding, and Loading
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Interface (class) definition, and Implementation
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Loosely typed when you want it
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12. Xcode Development Environment
Interface Builder for configuring Human I/F

Full IDE for Simulator and iPhone HW
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Instruments – Memory (leaks, guard-bands, &

object allocation), Performance, Timing, Graphics,
and lots more
Fine Grain Performance Analysis – Shark

Same tools as for Mac development
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Also used internally by Apple


13. Objective-C Example
@interface DemoAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow * window;
DemoViewController *viewController;
}
@property (nonatomic, retain) IBOutlet UIWindow * window;
@property (nonatomic, retain) IBOutlet DemoViewController *viewController;
@end
@implementation DemoAppDelegate
@synthesize window;
@synthesize viewController;
- (void)applicationDidFinishLaunching:(UIApplication *)app {
[window addSubview:viewController.view];
[window makeKeyAndVisible];
}
@end

14. Object-C Connectability
• Outlet – IB Connectable External Variable
• Protocol – Method set responded to by many
classes
• Delegate – Protocol-Outlet combination
• Target-Action – Dynamic External Methods
• Notifications – Central Message Dispatch
• Model-View-Controller Design Pattern

15. Protocol Example
@protocol UIApplicationDelegate<NSObject>
@optional
- (void)applicationDidFinishLaunching:
(UIApplication *)application;
...
@end

16. Toolkits and Frameworks

HI widgets: Menus, Touch I/F, Animations, etc
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WebView, ScrollView, ImageView, URLs

Mostly the same as for Mac development

iPhone specific
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– UI widgets (UIKit)
– Touch I/F
– Accelerometer
– Location (GPS)

17. References
iPhone Dev Center http://developer.apple.com/iphone/
Videos - Getting Started & iPhone Tech Talk World Tour
Coding How-to's
Sample Code
iPhone Reference Library
Apple Developer Forums and Google
Stanford iPhone Application Programming
http://www.stanford.edu/class/cs193p/

18. Summary
Application Landscape
Crowded, varied, and wide open
Application Production
As easy as iTunes
iPhone Technologies
Objective-C
Dynamic Connectivity
Expansive and expanding Dev Env and Toolkits