Original Post Date: Friday, September 2, 2011 

The IEEE published “Top 11 Technologies of the Decade” in the  January 2011 editions of the IEEE Spectrum magazine.  It should come to a surprise to no one that the Smartphone was number 1 on this list.  The answer to the author’s question “Is your phone smarter than a fifth grader” was a resounding YES![1] 

 In 1983 Motorola introduced the first hand hell cellular phone.  It weighed in at two and a half pounds, had memory capacity for 30 phone numbers, took 10 hours to recharge and had a selling price of $4000 ($8045 in 2006).  The phone was the size of a man’s head and would sustain an hour of conversation before a recharge was required.  In June of 2007 Apple announced that it was launching the iPhone which would basically integrate all of the electronic gadgets teenagers carried around in their pockets into a complete package – phone, web browser, iPod and camera.  The iPhone 5 which should be available by Fall 2011 incorporates NFC technology, an upgraded operating system with cloud integration, music streaming, voice interface, 4G connectivity and an embedded social networking tool. NFC technology makes it possible to use the phone effectively as a credit card – making payments by swiping the phone near a device that can read its information. [2][3][4][5]

The proliferation of smartphones and tablets has led (and will continue to lead) to the proliferation of mobile applications.  And it seems as there are no bounds to the kinds of applications that are being developed for smartphones.  A sampling of some popular applications is listed below:

* Chase Mobile – which allows users to check account balances and review transactions
* Angry Birds – very popular gaming software
* Facebook - allows users to report their status from anywhere
* Yelp – allows users to locate places to eat, shop , etc. along with reviews from local patrons of said establishments

The list goes on but clearly if you can dream it – there’s an app for that (or at least there could be an app for that).  As practitioners in the art of estimation, all this mobile application development leads to the inevitable question of what does it cost to develop mobile apps and how is mobile application development different from more traditional forms of development? 
Mobiles apps can be categorized as either native applications – which run entirely on the device or web applications - with small clients resident on the device which interact with applications running on a remote server.  It appears that in general the web applications are less complex than the native ones, and thus less effort is required to build, test and deploy them.
While mobile application development is still in its infancy so a lot of what is going on in the industry now has a bit of the Wild West feel to it.  This stage of any technology is impacted by learning curve issues which may dampen productivity but at the same time there is the newness factor – where smart people are excited about the promise of new technologies and are willing to work extra hard to make things happen.  So while there is some effort/cost data available for mobiles apps, we must temper our enthusiasm.
Another concern when developing mobile applications is which platform(s) it is being developed for.  If an application is being developed for iPhone, Android and Blackberry the effort is significantly increased.  Although there are elements of the design that can certainly transcend platforms, each of these platforms has its own operating system and development environment. There are additional potential compatibility issues in cases such as Android where there are multiple companies manufacturing devices. Additionally, application developers need to determine which versions of OS for each of the platforms the application will work with.  They also need to be aware of and respect the user interface guidelines developed for the device(s) for which they are building apps.
Mobile applications may need to respond to various forms of external data from sensors, a real or virtual keypad, a GPS, microphones, etc.  They also may need to respond to movements of the actual device as well - so the screen adjusts when the user changes the orientation of the device.  There are also many instances where mobile apps will need to interact with other applications on the device.  Often the mobile application will need to share elements of the user interface with other applications. 
Mobile applications need to be developed in such a way as to limit the consumption of resources.  No matter how good your killer app is, if it drains the phone battery in half an hour no one is going to use it.  Along with all other applications that have access to the Internet, they should be built with a focus on security so that the users data is protected from malicious intrusions.
All of the issues listed above are likely to impact the complexity of the development effort of the mobile application – thus they have the potential to be an important part of the cost equation as well.  In many cases mobile applications are smaller than traditional applications so increased complexity may be offset because the projects and corresponding project teams are small.  Still this increased complexity is important to consider.
Another area where mobile apps are dramatically different than traditional apps is in the testing of the application.  Simulators and emulators exist and can be helpful in some circumstances but they are not always easy to use, effective or efficient.  There are also issues, with some platforms around the maturity of the technology that allows applications to be transferred from the development environment to the mobile device – further complicating the testing process.  Finally there is just the sheer magnitude of making sure that the application functions correctly on all the combinations of hardware, operating system and carriers on which it will be expected to perform.  The cost and effort associated with testing may present significant differences when being evaluated for mobile applications.
Smartphones are here to stay and more and more businesses will want (or need) to develop apps for them in order to remain competitive.  With the technology still relatively immature there is limited data that will help us develop cost models but there is feedback from the field on what issues are most likely to impact costs.  Though the technology is still emergent – there is some data available from commercially based mobile app developments – so at least we have a place to start.
Share your experiences with mobile application development by leaving a comment for this post.

[1] Ross, Philip E., “Top 11 Technologies of the Decade”, IEEE Spectrum, January 2011
[2]  http://www.motorola.com
[3] http://www.apple.com
[4] http://en.wikipedia.org/wiki/Mobile_phone