Research firm Strategy Analytics recently released a report on global tablet shipments for the first quarter of this year, which shows Android taking the lead, having 66 percent share of the market. Apple's iOS follows with 28 percent, while Windows Phone takes 6 percent.

Tablet shipment for the period is 57.6 million units, an increase of 19 percent from last year's 48.3 million. Apple's share is a 19 percent decline from Q1 2013, as its iPad shipments fall below expectations. iPad sales for Q1 2014 is 16.4 million units, a 16 percent annual decrease from last year.

Director of Tablets Peter King at Strategy Analytics said that while Android tablets are grabbing a robust share of 38 million unit sales, iPads only sold 16.4 million units this year due to Apple's inventory change. However, the Cupertino iPad maker changed its product release schedule for the holidays, and there is a strong possibility that Apple may be back to lead the global tablet sales again, though iOS may continue to experience declining sales for the next few months.

For Windows Phone, the research firm acknowledges Microsoft's efforts of offering its mobile OS for sub 9-inch devices. If Microsoft is willing to cut prices of its tablets, they may become more competitive. However, there is still a problem in Windows Phone apps department as it cannot fare with Android's and iOS'. Microsoft for now fails to entice app developers with more incentives so they would work more on the Windows Phone platform.

The Strategy Analytics report covers the quarterly global shipments of tablets by OS starting from Q1 2010. Covered platforms include Android, Apple's iOS, Microsoft Windows Phone and BlackBerry.