Google, or at least Matt Cutts, may be congratulating Facebook on going public, but they are still rivals. They both want to connect the world in ways that allows them to service customers and sell ads. Google may think it has the home field advantage in specific areas, but Facebook has taken at least one Google property – Android.

The NPD Group released a study yesterday on the eve of the Facebook IPO that found over three-fourths of all Android users use their phones to access Facebook. That’s more than any other social networking service which makes Facebook king of Android. The reach doesn’t just extend to the Facebook app, but also mobile Web access.

Facebook’s app and Web reach are both sitting anywhere between 70 and 75 percent. That’s a massive number and one that the other social networking sites can’t even come close to matching. It was found that Twitter is sitting at second with only 23 percent reach in Web and 18 percent reach in apps. Google’s own service, Google+, has been lagging behind for the past nine months with only 16 percent reach in Web and 10 to 15 percent reach in apps.

Facebook is also dominating the amount of time people spend on apps. Users spend roughly 15 minutes a day on Facebook via Android devices which translates to 470 minutes a month. The amount of people spend on Facebook is second only to games, but NPD points out that Facebook is used more often with the average user opening the app six times a day.

“Ultimately, Facebook’s mobile success rests on delivering compelling mobile app and web experiences, and monetizing on these experiences,” said Linda Barrabee, research director, NPD Connected Intelligence. “In order to do this, Facebook needs to ensure that monetization efforts via advertising enhance and do not disrupt the mobile social consumer experience; and with Facebook’s IPO looming and trading expected to begin on May 18, all eyes are on the company.”

Facebook has taken this lesson to heart as Mark Zuckerberg has recently commented on the Facebook mobile experience. He says that the rise in mobile use has led Facebook to rethink their strategy of how they utilize mobile. There are not as many ads in the mobile Facebook experience so they’re losing out on all that delicious ad revenue when so many people now access the site via mobile applications.

While Facebook may be dominating the Android platform, Google can rest easy in the fact that they’re currently trading at $600 compared to Facebook’s $38. Sure, it may not seem fair to compare a company that’s been trading for years to one that just started trading, but all’s fair in love, war and tech IPOs.

[h/t: MediaPost]