In just two years the average time spent gaming on a smartphone or tablet has jumped from 80 minutes to over two hours a day and it's not just ‘tweenagers' who can't seem to put their mobile devices down.

In fact, mobile gaming is proving to be popular right into late middle age. According to the NPD Group's Mobile Gaming 2014 report, published this week, the average number of gaming sessions are at their highest from the ages of six to 44. However, it's those in their tween years (younger than 13) whose gaming sessions last the longest as a share of all their device time.

The report, which was compiled from the views of 5,566 US consumers aged two and above found that as well as playing for the longest amount of time per gaming session, two to 12-year-olds are playing a greater number of games (five on average) and are the most likely group to play premium (paid-for titles).

And while many industry commentators are already talking about the tablet's demise as a device that has been unable to stem off competition from bigger smartphones and affordable notebooks, NPD Group's findings highlight that when it comes to gaming, not only is the tablet still alive and well but it is the device, more than any other, that seems to be driving the trend.

Tablet owners play more games and play for longer than smartphone and iPod Touch owners and are more likely to pay for games and make in-app purchases.

However, as NPD's research covers the device habits of very young children as well as adults, the popularity of tablets is less surprising. Children are the most likely to play games and the most likely to pay for the longest periods of time and they're going to do it on the family tablet rather than a parent's smartphone.