This document provides guidance on boosting WatchKit apps, including engineering challenges, architecture, best practices, known issues, and thoughts. Some key challenges in WatchKit development are quick interaction, limited communication between the Apple Watch and iPhone, and strictly limited memory. The document discusses WatchKit app architecture and interface components like the main view, glance view, and notifications. It provides best practices such as avoiding UIImage methods and preparing data before the user opens the app. Known issues mentioned include the CFBundleName being ignored and needing to end background tasks. The document stresses testing on actual Apple Watch devices and that analytics will be important for understanding usage patterns of WatchKit apps.

2. Boost Your WatchKit App
Max Mai
Hepeng Zhang
Yahoo News Digest

3. Demo

4. Engineering Challenges
Architecture
Best practices
Known issues
Thoughts

5. Engineering Challenges
Architecture
Best practices
Known issues
Thoughts

6. Challenges
● Quick interaction
● Communication between iphone and watch
● Strictly limited memory

7. Engineering Challenges
Architecture
Best practices
Known issues
Thoughts

8. Architecture

9. Architecture
https://developer.apple.com/library/prerelease/ios/documentation/General/Conceptual/WatchKitProgramming
Guide/ConfiguringYourXcodeProject.html#//apple_ref/doc/uid/TP40014969-CH2-SW1

10. Interface components
● Main view
● Glance view
● Notification

11. Interface components
● Main view
● Glance view
● Notification

12. Interface components
● Main view
● Glance view
● Notification

13. Engineering Challenges
Architecture
Best practices
Known issues
Thoughts

14. ● Avoid UIImage methods.
Quick Interaction

15. ● dispatch_async
Quick Interaction

16. ● Prepare your data before user opens app
Quick Interaction

17. ● Avoid changing UI dynamically
Quick Interaction

18. ● NSUserDefaults
● Shared group container
● Watchkit special treat
+ (void) openParentApplication:reply:
- (void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void
(^)(NSDictionary *replyInfo))reply
But, reply info must be serializable as plist data.
Communicate with iphone app

19. ● NSUserDefaults
● Shared group container
● Watchkit special treat
+ (void) openParentApplication:reply:
- (void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void
(^)(NSDictionary *replyInfo))reply
But, reply info must be serializable as plist data.
Communicate with iphone app

20. ● NSUserDefaults
● Shared group container
● Watchkit special treat
+ (void) openParentApplication:reply:
- (void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void
(^)(NSDictionary *replyInfo))reply
But, reply info must be serializable as plist data.
Communicate with iphone app

21. ● Avoid UIImage.
● Be cautious when calling non WatchKit
framework methods
● addCachedImageWithData:name:
● Profile watchkit extension
Strictly limited memory

22. ● Avoid UIImage.
● Be cautious when calling non WatchKit
framework methods
● addCachedImageWithData:name:
● Profile watchkit extension
Strictly limited memory

23. ● Avoid UIImage.
● Be cautious when calling non WatchKit
framework methods
● addCachedImageWithData:name:
● Profile watchkit extension
Strictly limited memory

24. ● Avoid UIImage.
● Be cautious when calling non WatchKit
framework methods
● addCachedImageWithData:name:
● Profile watchkit extension
Strictly limited memory

25. Engineering Challenges
Architecture
Best practices
Known issues
Thoughts

26. Known issues
CFBundleName in watchkit extension target and watchkit
app is ignored.
Display name for your watchkit app is CFBundleName of
your main app

27. add background task that ends 2 seconds later after reply
Known issues
- (void)application:(UIApplication *)application
handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void (^)(NSDictionary
*))reply
{
UIBackgroundTaskIdentifier watchBackgroundTask;
watchBackgroundTask = [[UIApplication sharedApplication]
beginBackgroundTaskWithExpirationHandler:^{
[[UIApplication sharedApplication] endBackgroundTask:watchBackgroundTask];
}];
/**
Handle request
*/
reply(something);
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)),
dispatch_get_main_queue(), ^{
[[UIApplication sharedApplication] endBackgroundTask:watchBackgroundTask];
});
}

28. Best tips
https://developer.apple.com/watchkit/tips/

29. Engineering Challenges
Architecture
Best practices
Known issues
Thoughts

30. Thoughts
- Swift or Objective-C?
- Reuse iphone app code base?

32. Designing for the Apple
Watch
Yahoo Fantasy Sports App
Ed Lu - UX Designer
@superindustrial

33. Where we started

34. Where we started
Apple Watch Human Interface Guidelines
Glances, notifications, app views
PSDs & Sketch templates
Interactions are quick
Shouldn’t replace app

35. Fantasy design

36. Use cases
1. I’m on a date. Am I winning?
2. She’s in the bathroom. Winning by what margin?

37. Am I winning?
By what margin? (General)
By what margin? (Specific)
Glance App

38. Best practices

39. Dark themes
conserve
battery
Don’t be THAT app…

40. Get creative with
Glance
templates

41. Can your
animations

42. Everything looks
way too big in
comps so…

43. preview on
device at all
costs

44. I’ll be WATCHing you
Still too early to understand use patterns.
Analytics will be very important.

45. Thanks!

46. Flurry Analytics –
Apple Watch Support
PRESENTED BY
Brad Jones | Product Management, Flurry Analytics

47. Flurry Analytics – Extensions
47Yahoo Confidential & Proprietary
Flurry Reporting
 Compare Active Users
between Watch and App
 Events for Extensions
› Count
› Unique Users
› Unique Users as % of
App Active Users
 Funnels across App and
Extensions
Flurry Explorer
 Segmentation
 Funnels

48. Flurry Analytics
48Yahoo Confidential & Proprietary