The document discusses strategies for developing cross-platform mobile applications, emphasizing the importance of mobile in modern user experiences. It compares various development approaches, including HTML with PhoneGap and Mono, and outlines the considerations for targeting different platforms based on user demographics and app usage patterns. The author highlights the growing relevance of cross-platform solutions and provides guidance on optimizing development for multiple environments.

1. Cross Platform Mobility
Why and How to Build Cross Platform
Mobile Applications
Chris Auld
8 May 2012

2. WHY? MOBILE STRATEGY DISCUSSION HOW? MOBILE EXECUTION DISCUSSION
 Why mobile matters?  Value in unique user experiences
 Types of mobile apps  Cross platform options
 By user class  HTML+PhoneGap
 By technology approach  Mono
 Why cross platform matters?  Native x N
 Does cross platform matter?  Approaches to sharing code
 Which platforms?  Mono vs PhoneGap
 When?

3. Why

4. Why Mobile Matters
 Does anyone in the room *not* have a smart device?
 Anyone in your family 15yr-65yr *not* have one?
 What did you use 1st today, PC or Smart Device?
 How about last yesterday?
 Have you used an app today?

5. Morgan Stanley Research from 2009
Actual inflection
point

6. Types of Mobile Apps
BY USER CLASS BY APPLICATION APPROACH
Enterprise Web Apps
- Field force etc. - It works
SME/BYOD - It’s optimized
- Expense claims etc. - ICBINB
Consumer ‘Real’ Apps
- Mobile banking - Wrapped HTML
- Native

7. Why Cross Platform Matters
 Does it matter?
 Does need for enterprise apps kill BYOD strategy?
Application Approach Extra Cost Extra Dev Capex Org Size for Break Even
Web App/Wrapped HTML 20% $50,000 250
X-Platform Toolkit (Mono) 30% $75,000 375
Full Native 70% $175,000 875
Assume: Enterprise app build of say $250k
Assume: BYOD strategy to save $200/device via co-pay
Assume: Three platforms ‘supported’ for BYOD

8. Why Cross Platform Matters
 For Consumer/Public focussed apps it really does
matter.
 iOS has massive penetration in high value user
segments
 Android is bring Smart devices to the masses
 Microsoft is playing catch-up, but, is prepared to buy
share
 Think back to the first slide… how do you use mobile?

9. Which Platforms?
 Market share?
 Visitor share?
 Your site?
 Some other ‘common’ site?
You want to target, in priority order, the
platforms used by people most likely to use
their mobile devices to access your service

10. Which Platforms?
 IRD GST Site
Want to support filing GST return from mobile device
 Business users
 Blackberry is still very popular with business users
 Should we prioritize Blackberry? iOS?

11. Which Platforms?
 How do app usage patterns differ?
 Both Android and iPhone users D/L approx 10 apps
/month
 19% of Android users buy at least one app /month
 50% of iPhone users buy at least one app /month
*Admob Mobile Metrics

12. How

13. Different platforms are…different
Deserve different treatment at the UI level

15. Cross Platform Mobile App Dev
HTML + PhoneGap Mono
• Significant reuse • C# + .NET in • Platform specific
 Re-use web assets VS.NET UX
• Doesn’t look native • Can write highly
 Lambdas, LINQ
 Everything like iOS?
 Delegates, Events optimized code
• AppStore issues • Games
• Rich
• X-Browser issues
communications • Graphics intensive
• No offline on WP7
• Access to almost all apps
• Animations poor • Write the app 3
platform APIs via
• APIs unavailable times
Mono Wrappers
• Hardware access • Go native if needed • 3 different
• Platform specific • UI still written ‘by- languages
• It’s Javascript hand’ • 3 x code to maintain
 Must use OSS • Write UI for each • Objective C is awful
 Less productive platform +ve&-ve
100% Shared Code 0% Shared Code

16. Shared Code with Mono
 Shared files co-located; *.csproj for each platform
 Each solution has
 Platform specific project
 Shared project
 Similar MVVM pattern for all platforms
 Shared Models
 Shared Repository
 May be able to share ViewModels
 Can use shared Interface + Platform Specific Implementation
 WindowsPhonePreferencesProvider: IDevicePreferencesProvider
 Can use pre-processor directives
 #if MONOTOUCH
 Can support Windows Mobile easily. No support for Blackberry

17. Shared Code with PhoneGap
 All files co-located
 A solution has
 General purpose HTML + HTML templates
 Shared CSS + JS + Images
 Platform specific CSS + JS + Images
 Use MVVM or MVC pattern for all platforms
 Backbone.js/Knockout.js
 Share ‘everything’
 Complexity increases as platform count increases
 Each platform may require some specific shims
 Windows Mobile not supported & Older Blackberry OS is very hard to support
 Older phones may get a ‘bad’ experience

18. Choosing between PhoneGap or Mono
PHONEGAP MONO
 Existing advanced HTML+JS skills  Existing .NET C# dev skills
 Must have MVVM/MVC  Useful to have MVVM/MVC
knowledge knowledge
 Existing web resources  Complex communications
 A need/desire to support browser requirements
based viewing  Need lots of platform hooks
 Communications layer REST ready  Performance matters
 More productivity up-front
The smaller your organization and project the
more developer productivity matters…
Mono represents a high productivity choice even for pure one platform plays

19. Guidance By Intergen
Intergen staff have been involved in developing several reference
applications that are freely downloadable in source code form
 Project Silk http://silk.codeplex.com/ (Don Smith AKL)
Rich HTML+JS Web Apps.
 Project Liike http://liike.github.com (Don Smith AKL)
Rich HTML+JS Mobile Web Apps.
 StockTrader v6 https://azurestocktrader.cloudapp.net/
(Chris Auld/James Carpinter WLG + others)
Massive scale Azure based app with cross platform rich client for
iOS, Android, WP7, HTML5+JS, Windows Metro (Mono based)

20. Mobile Matters – Mobile First
Do you *really* need x-platform
Phone + Mono both useful options

21. Questions

22. Thank You