Tops of 2015: Digital

From videos to music to apps, digital was at the forefront of consumers’ (and marketers’) minds this year. As 2015 comes to a close, Nielsen looked at some of the top trends in digital, including the top U.S. smartphone apps and operating systems. In 2015, Facebook again took the lead as the top smartphone app. The social networking app had more than 126 million average unique users each month, a