When it comes to choosing a smartphone – or any device, for that matter – the hardware and OS are the deciding factors. But with so many devices on the market, it becomes necessary to differentiate the various manufacturers. The most common way of doing this is to customize the OS, adding features on top of the basic operating system. Microsoft, however, does not allow handset makers to customize the Windows Phone OS. As a result, companies have turned to exclusive apps to help their devices stand out from the crowd. No manufacturer has done a better job of this than Nokia.

For Nokia, exclusive high-quality apps are crucial for selling new devices and increasing customer loyalty. Companies like Samsung and HTC have done a decent job in the app department, but they’re mostly apps which have been developed in-house. And, unfortunately, none of the apps could be considered a must-have. Nokia, however, offers a stellar lineup of first-party apps, and the company has gone out of its way to encourage developers to hop on the Windows Phone bandwagon.

Over the last few months, Nokia has managed to convince a number of high-profile developers to bring their apps over to Windows Phone. The list includes sports apps like PGA Tour, ESPN Fantasy Football, and an updated ESPN Sports Hub; EA games like FIFA, Madden, NBA Jam, Tiger Woods, Mirror’s Edge (which was released today), and Yahtzee; PayPal; Groupon; AOL Entertainment Hub; TripDots; TIME; NewsWeek; Box; Rovio games like Angry Birds Space and Amazing Alex; and Zynga games like Draw Something and Words With Friends. Many of these are timed exclusives, so they’ll be made available through the Nokia Collection somewhere between three and six months ahead of the rest of the Windows Phone Marketplace. This is in addition to Nokia’s excellent suite of first-party apps like Nokia Drive, Nokia Maps, Nokia Transit, Nokia Trailers, Nokia City Lens, Creative Studio, App Highlights, Play To, Camera Extras, and many more.

When Microsoft announced Windows Phone 8 a few weeks ago - a major revision to the OS which is not compatible with existing hardware and provides new ways for developers to create apps – many current Windows Phone owners became concerned that their hardware was suddenly outdated. Nokia Lumia 900 owners, especially, were frustrated, given that the phone was only released in April. Would they be left behind for the remainder of their contract? Thankfully, Nokia doesn’t want to leave its customers in the dust. One of the ways it intends to solve this problem is through a steady stream of apps for Windows Phone 7.x devices. They might not be able to get all of the new WP8 features – except for the new Start screen, which will be delivered in the Windows Phone 7.8 update this fall – but great apps like the ones listed above should help extend the lifetime of Nokia’s current device lineup.

For most manufacturers, apps seem to be an afterthought. But for Nokia, they couldn’t be more important. If the company can continue to release excellent exclusive apps for Windows Phone 7.x devices – at least for another year or so – then Lumia 900 owners won’t have to worry. In fact, I’d argue that with above lineup, the Lumia 900 is still worth picking up. Of course, Nokia is also doing the entire Windows Phone ecosystem a favor, as once the timed exclusivity deals expire, every Windows Phone will have access to the apps Nokia worked so hard to acquire. In the meantime, it pays to be a Lumia owner because, when it comes to Nokia, it’s all about the apps.