Since Apple Inc. launched its highly anticipated tablet iPad on April 3, 2010, users of the world's most popular tablet have downloaded a total of three billion apps, or nearly one-fifth of all apps downloaded from the Apple App Store, according to Allied Business Intelligence Research.

It has taken only one and half years to achieve the result, and surprisingly, faster then what iPhone has done, which had taken two years to reach the same milestone.

In contrast, Android tablets boast of 440 million app downloads so far. Without doubt, the gap between app downloads for iPad and Android tablets is glaring.

No wonder, research associate Lim Shiyang said, Discounting all those apps that were originally developed for Android smartphones, Android still trails greatly behind the iPad in terms of its tablet app offerings.

Many Android tablets in the market are still using older versions of Android, which disadvantages users from enjoying the better effects of apps produced from more advanced software development kits, Shiyang added.

In fact, apps for iPad are growing faster than those for Android tablets not only in terms of quantity, but also in terms of quality. As of Q3 2011, 120,000 apps were published specifically for the iPad.

“In terms of hardware, the iPad device still offers much more compared to the current crop of tablets in the market,” Dan Shey, ABI Research's practice director of mobile services, commented. Android is currently being used on many low end tablets that do not offer experiences anywhere near the iPad and this dampens the download momentum for users.

Nevertheless, ABI Research expects the Android tablet manufacturers to improve hardware specifications and product development to narrow the gap between Android tablets and iPad.

Among three billion apps for the iPad, it's pretty difficult to choose the most popular apps. However, after careful review, Tech&Trend has compiled a list of the top 10 must-have iPad apps.

Start the slideshow to check out whether you have downloaded any of them.

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