Windows phones accounted for just 3 percent of global smartphone sales last year, compared with about 81 percent for devices with Google's Android system and 15 percent for Apple and its iOS system, according to research firm IDC. One reason is that Windows doesn't run as many or as attractive apps as its rivals.
               
To boost sales of its phones and new operating system, Microsoft said last month that it would provide tools to software developers to make it easier to design apps for Windows based on apps that run on Android or Apple. But because so few people use a Windows phone, most developers remain focused on the more popular systems and don't see a need to develop apps for Windows. They also said they doubt how easy the new tools will be to use.
               
"Windows phone will have to gain a significant share of the market before this becomes something that saves us time and/or money," said Sean Orelli, a director at app development firm Fuzz Productions in New York, which makes apps related to Citibank, the New York Post, and Conde Nast, among others.
               
For Microsoft, the world's biggest software company, there's a lot at stake this summer as it rolls out Windows 10, the first operating system designed to run on PCs, tablets and phones. If developers don't embrace the new platform, it will seriously damage the prospects of the new operating system, which Microsoft hopes will power one billion devices in two or three years.