• by Mark Walsh  @markfwal, January 23, 2013

Facebook topped the list of top mobile apps in 2012, thanks largely to Apple replacing Google Maps with Apple Maps on iOS 6 in September.

According to new comScore data, Facebook’s U.S. audience on iOS and Android devices rose from about 63 million to 85.6 million from March to December, while the Google Maps audience tumbled from more than 80 million to over 70 million between September and October.

The drop happened after Apple dumped it as the default mapping app on iOS 6.

Google Maps finished the year second to Facebook, with 74 million monthly visitors, after Apple reinstated the app as an App Store download in mid-December following widespread criticism of its own mapping tool. “Google Maps has been clawing its way back the past few months after getting reinstated on iOS 6, so look for the competition for the #1 spot to heat up as we head into 2013,” noted comScore’s release.

Google may have lost the top spot to Facebook, but it still claimed five of the top six apps. In addition to Google Maps, that includes Google Play, Google Search, Gmail and YouTube. Rounding out the top ten were Pandora, iTunes, Cooliris and Yahoo Messenger.

In addition to the largest audience, Facebook also ranked highest terms of mobile app engagement. It accounts for nearly a quarter (23%) of time spent with apps, with sister app Instagram chipping in another 3%. Several Google apps collectively account for 10% of time spent in apps, with Gmail commanding the biggest share individually, at 3%.

All other apps drive 64% of time spent. Despite the rise of other social apps including Instagram, Pinterest and Twitter, the figures show how dominant Facebook remains when it comes to engagement.