With the number of application stores growing rapidly, developers need to have a strategy for creating applications for mobile devices, according to Forrester analyst Jeffrey Hammond.

“Who is your target? Is it a consumer- or business-focused [strategy]? Consumers tend to favor Apple and Android while business [is dominated] by RIM/BlackBerry,” he said.

Then, he said, developers need to consider if the application will be a “native” application or a portal to an optimized website. The average cost to develop a mobile application is US$6,453, according to an article written by Alex Ahlund, former CEO of AndroidApps and AppVee, and later an advisor to Appolicious. OS X Daily reports that the estimated range for small applications is $3,000 to $8,000, and more complex applications can cost from $50,000 to $150,000.
Once a developer determines which strategy is best, he or she must pick an application store to begin the process. Hammond said that developers should, instead of developing all applications for multiple mobile OSes at once, develop in a “serial” manner to determine which features can be used throughout those OSes.

Next, a monetization strategy should be determined, according to Hammond. He said there are three options: “Sell the app, use it to drive advertising revenue, or tie it into a larger service.” Many individual programmers, he said, choose to create an application and earn revenue from sales of the application instead of from ad programs available in the app stores. Others, he said, choose to use a variety of ad programs available through the mobile device vendors and app stores.

Hammond said that for consumer applications, selling the application works best on the iPhone as the users are “conditioned” and “more likely” to purchase applications because of their reliance and familiarity with the iTunes music store.

Android users, on the other hand and according to Hammond, were originally conditioned to use free applications, as all applications in the Android OS were initially required to be free by Google. As such, they are less likely to make purchases from an app store, preferring to find free downloads instead.

Developers also need to determine how many rules they want to deal with, according to Hammond. He said that Apple is much more “picky” about what developers do, and that developers using iOS need to “stick to the rules” to have a successful application. Android, he said, has more freedoms for developing applications.

BlackBerry, according to Alex Kinsella, senior product manager for BlackBerry App World, also has freedom for developers. BlackBerry’s developer group allows developers to target Flash or WebWorks, which is a device OS powered by a WebKit browser. The development tool is supplied by BlackBerry as a plug-in for Eclipse and Visual Studio, and also has a development environment for their themes, so the entire BlackBerry OS is exposed for developers.

Hammond concluded that a successful strategy includes an expectation that approval processes, where applicable, will take an “indeterminate amount of time, in the Apple store specifically.”

When choosing the device and OS, Hammond said, developers are mostly concerned about how many units they will be reaching and how large the market it.

Mobile phones with Android hold 29% of the market, while BlackBerry and iOS hold 27% each, according to figures released in March by NielsenWire, a consumer market research firm. Windows Mobile/Windows Phone 7 holds 10%, and webOS by HP/Palm falls at the bottom with 4%.

Hammond said the app stores held by the devices are no longer the trend; private app stores, such as those created by Apperian and JackBe, a mobile device management store to provision business applications, are the future.

“Self-service is clearly a future trend,” Hammond said, referring to consumer and enterprise markets.

App stores side by side
Which app store is the best? We leave that up to you to decide, but this should help you understand the differences between them.

The Apple App Store and Mac App Store
The store that coined the term (and is fighting Microsoft to protect it) claims more than 10 billion application downloads as of January 2011, along with more than 350,000 applications. Apple takes a 30% cut from sales of individual applications and requires payment to be made through the iTunes billing system.

The App Store is pre-installed on every mobile device, and the Mac App Store, a separate, new application store for desktop applications, is also packaged with every desktop and laptop sold by the company. Apple also has its own advertising program—iAd—that allows developers to monetize their applications through Apple’s development site. The iAd program is for both consumer brands and developers, and it allows users to view a commercial, buy an application (which is how developers utilize the service for additional applications produced) save, and share information on social networks.

Recently, Apple announced a “new subscription service available to all publishers of content-based apps on the App Store, including magazines, newspapers, video, music, etc.” CEO Steve Jobs reportedly followed up this release with an e-mail that said that software-as-a-service (SaaS) applications, such as Dropbox (an application that allows end users to access data that is stored on Dropbox’s cloud), would not be included in this model. It is unclear whether applications for reading websites, like Evernote, will be included.

The App Store developer program for iOS has a yearly fee (starting at $99), which includes access to the tools in the iOS Dev Center, including the Xcode SDK, developer forums, testing tools, reference libraries, and coding resources.

There is an approval process for an application submitted to the App Store and requirements, which Apple declined to provide. Distribution of applications to the App Store allows developers to name their price and claim 70% of the profits on individual applications sold. Apple waives all fees for free applications submitted to the store; often these are the applications that run on the ad-revenue model described by Hammond.

Enterprise developers can also join the enterprise developer program for $299 per year to distribute in-house iOS applications. Organizations are required to have a Dun & Bradstreet number, and developers have the same rights and restrictions as those developing consumer applications.

The fee to join the Mac Developer Program for the Mac App Store is also $99 yearly, and developers also receive access to early versions of the OS environment as well as a kit to develop apps for the Mac App store. Apple, according to a press release, launched the Mac App Store in January with more than 1,000 apps.

The Google Apps Marketplace and Android Market
Developing for the Android OS, for tablets and mobile phones, is available for free via Google’s Android Developer site. Android applications are written in Java, and Google allows developers to access all tools, support and framework information on its developer site.

The Android SDK compiles the code, data and resource files into an “Android package” to sandbox the applications in order to limit access only to the functions required to make the applications work, and to not interfere with other native applications on the device or the device itself, according to the company. Google recommends the Eclipse IDE; however, developers are allowed to use other tools as they see fit.

Developers are allowed to use in-app billing provided by Google’s Mobile Ad program (a partnership between Google and AdMob, which Google acquired in May 2010) for monetization, as well as a new subscription service, One Pass, announced in February. Google also lets developers keep 70% of the mobile apps profits, like Apple and RIM, for application sales as well as in-app purchases.

Google also provides an “application checklist” for developers to use prior to publishing their apps to the Android Market. Developers are required to test extensively on actual devices, debug, add licensing support and sign their applications, among other requirements.

The application development program is free, but developers are required to pay a one-time $100 fee to list their first applications.

The tools also are free, and developers have access to support and forums. The only required integration, according to Google, is the use of the single sign-on application.

Pricing can be determined in a variety of ways, including charging for multiple editions, or as a subscription attached to a free trial period. Applications may be released free of charge as well.

BlackBerry App World
Alex Kinsella, senior product manager for BlackBerry App World, said that the BlackBerry App World has more than 20,000 applications and 6,000 developers, and that the split of the profits is currently 70% for developers and 30% for RIM. There is no fee structure for development programs for the BlackBerry, he added.

“App World 2.1 has in-app payments, freemium versions [versions that allow for a trial before buying a full version of the application], and developers can sell items inside the app if they want to,” Kinsella said.

Flexibility, he said, is an important characteristic of the BlackBerry Developer Program.

WebWorks works across the BlackBerry and PlayBook tablet OS environments, and Java applications can be developed for the BlackBerry [mobile devices],” Kinsella said.

He added that RIM also offers the BlackBerry Advertising Service, in which developers receive 60% of the revenue earned from the advertisements, while RIM takes a 40% cut. The Ad Service is a compilation of several different ad programs, and RIM allows developers to determine which market is most relevant for their application.

The application approval process for BlackBerry devices averages 10 business days, although Kinsella said that very complicated applications or themes—particularly those with copyrighted images—could take a little longer.

Themes (or how the OS of the device appears to the end-user) are the most popular “application” submitted for the BlackBerry, Kinsella said. They are assembled with Theme Builder, and all SDKs are free and available, he said.

Intel AppUp Store for Netbooks
The Intel AppUp store for Netbooks allows end users to download applications directly to their netbook computers. Applications range from games to productivity applications and beyond.

Its developer program originally had a $99 annual fee, but as of March, the program was free to join. This includes an SDK, support and, with the program membership, the right to submit applications to the store.

Developers can create applications in Adobe AIR, Java, Silverlight or Windows. Developers can also create applications for MeeGo, the result of collaboration between Intel and Nokia for the tablet environment, which Intel has taken over after Nokia’s alliance with Microsoft.

After applications are created, they need to be submitted to Intel for validation, and Intel provides an “application readiness checklist” that outlines the guidelines for applications to be approved. Those include provisions for protection and security, licensing, installation, and prohibited activities.

Developers are prohibited from distributing their applications to other marketplaces; promoting or linking users to websites that encourage or require users to pay or purchase upgrades outside the App Store; using pop-up ads; and distributing free applications that encourage upgrades from within the application, according to Intel.

Windows App Hub
The Windows App Hub program allows developers to create applications for Windows Phone Marketplace, Xbox LIVE Marketplace and Windows-based computers. There are 32,000 registered developers in the Windows Phone development program, and more than 9,000 applications are offered in the Windows Phone Marketplace app store, according to the Windows Phone Developer blog.

The Windows Phone developer tools free download package, available in multiple languages, includes Visual Studio 2010 Express, the Windows Phone Emulator, XNA Game Studio 4.0, Microsoft Expression Blend for Windows Phone, Silverlight, and .NET Framework 4. If developers already have any of these or Visual Studio 2010 Professional, the smart installer will install only the components needed to complete the development environment, according to the App Hub website.

The subscription for a developer program membership is $99 annually, and it grants access to Windows Phone, Xbox and Windows for desktops. The App Hub allows users to access support and forums as necessary.

Microsoft changed the requirements of its app store and developer program in March to include trial applications, which are ad-funded applications using its ad control program. It also raised the number of accepted free applications from five to 100.

Palm App Catalog
The HP Palm webOS development program is free and applicable to both mobile and tablet applications for the HP Palm webOS system. It is purchased in the WebOS Palm App Catalog and includes an SDK, APIs, and a variety of tools and forums.

The HP Palm Ares program is a mobile development tool that is hosted in a browser; it allows developers to submit applications to the Palm App Catalog as well. It is accessed through a developer’s free Palm developer account.

The HP webOS platform SDK and PDK plug-in development kit are available for both Mac and Windows OS-based computers, and the SDK is available for Linux-based machines as well. The PDK lets developers use C and C++ alongside the Web technologies that power the SDK, and even mix them seamlessly within