In 2013, about half of console gamers in the United States played on smartphones and tablets, Nielsen found.
Console gamers (over 13 years old) who also play on mobile devices and tablets (2011 – 2013)
In total, American gamers spent an average of 6.3 hours a week on games (on any platform).
Time spent by gamers on all platforms per week (2011 – 2013)
Of these hours, on average, mobile games accounted for 19% or 1.1 hours per week.
Segmentation of time spent by users on games by platformsSource: http://www.nielsen.com