In 2016, Facebook once again took the lead as the top smartphone app, according to an annual roundup from Nielsen.
In fact, the social giant had more than 146 million average unique monthly users -- up 14% from 2015.
Showing its mobile dominance, Facebook’s Messenger app took second place, with over 129 million average unique users each month.
Google’s YouTube came in third, with more than 113 million average unique users each month.
Meanwhile, among the top 10 smartphone apps, those with the highest year-over-year change were Amazon App and Instagram -- with 43% and 36% growth in users from 2015, respectively.
More broadly, smartphone penetration grew to 88% of U.S. mobile subscribers at the end of September 2016 -- up from 86% at the start of the year.
In the third quarter of the year, a majority of subscribers used Android (53%) and iOS (45%) devices to access their apps.
Trailing far behind, 2% of U.S. smartphone owners used a handset that operated on a Windows phone, followed by 1% on a BlackBerry.
Nielsen’s Electronic Mobile Measurement system is responsible for these findings. It's installed with permission on panelist smartphones -- approximately 9,000 panelists ages 18 and up with Android and iOS handsets.
The panelists are recruited online in English and include Hispanic, African-American, Asian-American, Native American and Alaskan Native and other mixed racial background consumer representation, according to the research giant.