The MLB.com At Bat app perennially jumps to the top of the charts when the latest version is released at the start of each baseball season. This year’s edition is no different, ranking as the top-grossing app for the iPhone and Android since its February release. It has also been the top-grossing app for the iPad.

What’s new is that At Bat 12 has hit the 3 million download mark only eight days into the regular season, a level it took until August 22 -- 145 days into the season -- for the app to reach last year.

Since baseball’s opening day April 4, the new At Bat app has delivered a daily average of over 800,000 live audio and video streams, roughly double last year's rate.

It’s likely that the steep rise in iPad adoption has been a key factor in accelerating downloads. Apple sold nearly 40 million iPads worldwide in 2011 and the newly introduced model appears to be off to a strong start in 2012. More people have iPhones and Android devices now too, with Nielsen estimating that smartphone penetration has reached nearly 50% in the U.S.

For its part, MLB.com added performance enhancements like high-resolution graphics for Apple’s Retina display on devices, while keeping the season subscription price at $14.99.

That isn’t to say that the popular app, which so far has earned a 3.5-star rating in the App Store, is without complaints. One reviewer groused about full-page ads accompanying each news article, while others lamented box scores not being included in the free content. There are also the usual gripes about the $15 subscription fee-- well above the $1 or $2 typically charged for an iPhone app.