While many app developers have merely reworked their Android or iOS apps to function on Windows Phone 7, a handful of independent app makers are developing exclusively in Microsoft's mobile operating system. Why are these bootstrapping coders throwing all of their (spare) time behind the insurgent OS, and not Android or iOS?

For some, it’s because there’s less competition on WP7, or because they’re most familiar with Microsoft’s tools, or because they simply don’t care for the way iOS and Android operate. Microsoft is fighting to exploit those beliefs and recruit the developers who hold them; the company's success or failure at doing so may mean the success or failure of the Windows Phone 7 platform.

With just over 30,000 apps available for WP7, and only 2 percent of the United States smartphone market, Microsoft is a very small fish in a very competitive pond. But it is growing: According to Microsoft’s stats, Windows Phone 7 gained some 5000 apps in the past two months. Sure, that’s nothing next to the half-million apps on iOS, and the 200,000 you can find on Android, but WP7’s growing apps store shows that some developers think the platform is worth the time and effort.

Hearing the Good Word: Microsoft Evangelists and Thumba

At the moment, Microsoft is still trying to get its little app garden to flower. When Windows Phone 7 hit the market early last year, reports said that Microsoft was offering free equipment, revenue guarantees, and even cash incentives to developers to make apps for the WP7 platform, something that Apple and Google have never had to do for iOS and Android.

Microsoft representatives won’t comment on whether the company still pays developers to make apps, but Microsoft isn’t shy about the fact that it is attempting to lure developers, employing “more than 1000 ‘Microsoft Evangelists’ around the world,” according to Matt Bencke, general manager of Windows Phone apps for Microsoft. These globe-trotting Evangelists seek out developers at iOS and Android developer conferences or at grad schools, or they host hackathons in an effort to “convert” programmers to the WP7 platform.

“The hard reality of our competitive life is, we have to go where the developers are,” Bencke says. “We realize we're in a bit of an arms race, and the number of apps we have matters.”

The Evangelist method has seen some success. It’s responsible for Thumba, a photo-editing app that rivals most of the image-editing apps on iOS, and pretty much every photo-editing app on Android.

The developers, Pieter Voloshyn and his partners Luiz Thadeau and Jhun Iti, were working on a prototype photo editor using Microsoft’s Silverlight at The Methodist University of São Paulo in Brazil a few years back. Voloshyn says that a Microsoft Evangelist based in Brazil heard about their project and reached out to him and his partners, supplying the three with a Windows Phone 7 device and allowing them to submit the app before the app store opened in 2010.

Although Voloshyn says the team hasn’t made any money from Microsoft for developing the app, they have made a considerable sum selling the app itself, which costs $0.99. WP7 developers usually keep 70 percent of their earnings from the app store. Voloshyn notes that even though he couldn’t live off what he makes from his app, its earnings did help him pay for his recent wedding and honeymoon.

Voloshyn isn’t starry-eyed about Microsoft’s position in the smartphone game, but being recruited by Microsoft was a positive experience for him. “I think the [platform] leadership will be shared among the three [Android, iOS, and Windows Phone 7]. Microsoft came late in the game but came well, and I see a lot of gas for WP7 to compete,” he says.

That said, when asked what kind of phone he owns, Voloshyn admitted that he still uses a feature phone: “I’d love to have a WP7, but the price here in Brazil, when it comes, is charged with so many taxes that it discourages me. But I still have a hope of getting it with a fair price.”

Astoundingly, even among developers, Microsoft needs to fight to make owning a Windows Phone 7 handset--and using it for everything in day-to-day life--a priority.

A Labor of Love: Feed Me

Calum McLellan’s story is a bit different. A New Zealander living in Germany, he works at a German software company, programming a data-management system. He wanted to try creating mobile apps, and he figured he’d have enough spare time to do a little coding in the evenings after he put his son to bed.

“I was considering starting with Android last year, but then WP7 came out,” McLellan says. “I have a lot of experience with Windows Presentation Foundation, Windows Communication Foundation, and Silverlight. I was also turned off by Android due to the number of apps available, the poor average quality of the apps, and the lack of developer support. I didn't want to work with Apple because it’s very difficult for someone without a Mac. And, in my opinion, these are the only three mobile platforms really worth considering at the moment.”

Despite clocking over 45 hours a week at his full-time job, McLellan created the app Feed Me, a mobile RSS feed reader, and released it in early 2011. He said he spends about 10 hours a week keeping up the app, and about 30 to 40 hours a week right before he releases an update. He plans on issuing one more update before releasing a Mango version this fall.

But has he made any money? “Not right now. I sort of hope that in a couple of years I can get a chunk of money,” he says. The ads that run in his free app have earned him a little cash, but require a U.S. bank account for him to withdraw the revenue (until the ad-placement service expands to Europe, which he hears will happen in a couple months). Regardless, the earnings are modest: “Windows Phone doesn't quite have enough market share at the moment,” McLellan admits.

He still thinks Windows Phone 7 is a better platform, because it’s an enclosed consumer phone like the iPhone, rather than an open-source mess of possible tweaks and adjustments. “I spent quite a while with Android last year, looking at the two OSs. With Android, I just couldn't stop messing with it, and that drove me nuts. Windows Phone saves me a lot of time.”

Still, the slow profits are a concern not just for app developers but also for Microsoft, who clearly wants to see app makers win big. Microsoft’s Bencke says the company has been predicting a gold rush for developers. But where is that rush? “It's 1847 for us, and the '49ers haven’t arrived in droves," he says, laughing. "We're seeing lots of positive signs, and we do have developers who are making great money. It's early in the gold rush.”

The Company Line: Social Lookout

While McLellan is a somewhat “platform agnostic” developer who actively chose between Windows Phone 7 and Android, Geert van der Cruijsen became a WP7 developer because he was already working a lot with Windows software creation tools. van der Cruijsen is Dutch and works as a consultant at Avanade, a company that builds software using Microsoft technologies.

His company had a contest to see who could build the best WP7 app, and he came in second with his app Social Lookout, which allows the user to follow tags and trends--rather than individual people--on social networks. He tied up some of the app’s loose ends after the contest, and submitted it to the Windows Phone 7 app store. Since then, he has worked on a few more WP7 app ideas outside of work, including his recent app PinPin ATM Locator.

Even so, van der Cruijsen is pragmatic about Windows Phone’s potential. “I don't see WP7 catching up to Android anytime soon. I think Windows Phone 7 has more potential than iOS, except for the coolness factor that Apple has for some reason.” His app development remains a hobby and hasn’t made him any money, although he’s working on paid and ad-supported apps for the future.

Like McLellan, van der Cruijsen expresses displeasure with how easily average users can get lost in the überfunctionality of the Android platform. “Android is really open, so it has more potential, but it is also a danger because it can get to hard to use for nontechnical people,” he says. Android is now the leading OS for smartphones, but developers like McLellan and van der Cruijsen prefer to give customers apps that they won’t have to “fiddle with,” subscribing to the idea that there’s potential in constraint.

And van der Cruijsen thinks Mango is round two for the fighting OS: “Windows’ Metro UI is really adding something, and I like that lots of things are integrated in the OS that you use a lot, like Facebook and Twitter.”

Fortunately, the passion for good apps is out there among Windows Phone 7 developers, even as Microsoft continues to struggle in making its phone a ubiquitous device. And Microsoft’s Bencke seems to have his heart in the right place when it comes to working with the grassroots: “The developers absolutely deserve to make money. The investment is pretty reasonable, whether you're a rookie or an experienced developer; we go out of our way to help you out.”