AT LAST: Instagram Arrives On Windows Phone

It's been nearly three years since Microsoft released its new Windows Phone operating system, and it finally has one of the most sought after apps: Instagram.

Instagram officially lands on Windows Phone devices later today along with another popular app already on Android and iPhone called Waze. (Waze is a mapping application that's now owned by Google. Its users report items like traffic accidents and reduced gas prices that appear in the app.)

Microsoft couldn't be more giddy that Instagram, Waze, and a handful of other big-name apps like Flipboard and Vine are finally coming to Windows Phone.

Speaking to Business Insider, two members of the Windows Phone app store and marketing teams said the platform is finally big enough to start attracting the big-name apps people want to use.

"While our global market share is around 4%, it's still the fastest growing," said Todd Brix, the general manager of the Windows app store. (He was talking about Windows Phone market share.) "Developers are smart and they'll invest where opportunity is going."

Brix has a point. Nokia, the biggest maker of Windows Phones, continues to report increasing shipments of its Windows Phones quarter over quarter. It shipped 8.8 million Lumia-branded Windows Phones last quarter.

But in reality, things aren't quite so rosy for Windows Phone and even Android, which has a whopping 80% of the global smartphone market. Developers still tend to make apps for iPhone before moving on to Android or Windows Phone. That means non-iPhone users often have to wait months to get the hottest new apps and app updates.

Microsoft's next challenge isn't necessarily to get the current library of hot apps on Windows Phone (but that helps!), it's to make sure developers think of making stuff for Windows Phone right off the bat.