Microsoft's (MSFT 0.46%) Windows Phone has an apps problem, only it's not the one most people think it is.

One of the more commonly cited arguments made against switching to the third-place phone OS is the lack of apps available in the Windows Phone app store. That argument appears reasonable. However, when you look at the numbers, the argument falls apart under closer scrutiny.

Yes, according to BGR.com, there were "only" 300,000 plus apps in the Windows Phone store when Microsoft made the number public last August. That's only a fraction of the one million plus offered for Apple (AAPL 0.51%) iPhones and phones running Google's (GOOG 1.43%) (GOOGL 1.42%) OS.

That looks bad for Microsoft and it makes for good headlines, but you have to consider whether the difference between over 300,000 and 1 million apps actually matters when the average person uses, according to research from Nielsen, fewer than 30 apps per month. That simple fact makes the gap between the size of the app stores less relevant if Microsoft has most of the most popular apps, which it does (as can be seen below). 

All of this being said, Microsoft does have a different kind of app problem. Only instead of it being the number of apps in its store, it's the infrequency with which its apps are updated. The problem for the Windows Phone is not its lack of having 7,000 flashlight apps and a few hundred Flappy Bird knockoffs (it has plenty of each). It's that the company had the muscle to get a lot of top app providers to launch Windows Phone 8 apps but not the muscle to keep them there when the relatively tiny audience for the phones gave them little return on their investment.

The tops apps are (mostly) here
Of the top 10 apps in Apple's app store as of March 10, the Windows Phone store has Facebook Messenger, Facebook, Instagram, YouTube, Pandora, Trivia Crack, Spring Ninja, and Google Maps. The only things missing are Apple's own iTunes U app (for obvious reasons), and Snapchat. Moving down the free list and it becomes clear that Windows Phone has nearly all the top titles. The same is generally true on the paid side where Microsoft's store has nearly all the big name apps and approximations or alternatives for the less-famous big sellers.

So, what's the problem?
Microsoft has a good selection of apps on the surface, but when you dig a little deeper you see that many companies launch a Windows app then don't update it at all. For the apps that are eventually updated, the actual update lags far behind the versions in Apple and Google's stores.  

This isn't a problem as much for the absolute top-tier apps, but it has been an issue among the next level of apps. For example, Major League Baseball will not be updating its At Bat app for Windows Phone for the coming season, according to Windows Central. In addition Bank of America pulled support for its Windows Phone app March 1 joining Chase which dropped support for its Windows Phone app earlier this year, according to PCWorld . Wells Fargo has a Windows App that it supports, according to the article, but the bank has made no effort to update it work with the Windows Phone's wallet feature. 

Microsoft actually has a developer's code of conduct which requires apps to be updated, but that has not stopped many of the big players from updating their products far less frequently than they do in the Apple and Google stores. Instagram, for example, has not been updated since March 22, 2014, while the Apple store version was updated on March 5, 2015, and the Google Play edition was updated on Feb. 27, 2015.  

The same story is true for countless other top apps. It's not a universal problem, but it's a big enough issue that it's likely to sour the Windows Phone experience. 

Microsoft has a solution for this 
The reason apps are launched and then left to whither and die is that Windows Phone has less than 3% market share. Almost the entire rest of the market is dominated by Apple's iOS and Google's Android.

Source: Statista

That makes it very important for app makers to keep Google and Apple customers happy, but much less enticing for them to do anything for the scant number of Windows Phone users. Fortunately, for Microsoft, and Windows Phone fans, the company is doing something which will make this problem go away.

When Windows 10 is released, the new OS will have a universal app store across PCs, tablets, and phones. That will take the tiny audience of Windows Phone customers apps were developed for and blow it up to every person who owns a Windows machine of any type. That number may not be as big as it was before Android tablets and iPads leached into the PC market, but over 80 million PCs were shipped in the fourth quarter of 2014, according to IDC.

Yes, 5.75 million of those were Macs and millions more are running Google's Chrome OS (IDC does not break out that data) but the vast majority are PCs running Windows. The Windows Phone app audience may be too small for companies to regularly update their apps, but the combined Windows user base will almost surely not be.

It will take time as many PC users will wait to update, but Windows 10 and its universal apps store, solves Windows Phone's app problem.