Look around you on a train, a bus or a waiting room and you will see others gazing at screens as life passes them by.
It is more and more likely those people will be playing some of the thousands of downloadable games that have taken our downtime by storm.
It used to be the colourful characters of Angry Birds that had players swiping and poking on their phones.
But now the world's most popular app game is Candy Crush Saga, a puzzle in which players assemble identically coloured sweets to move up through its many levels.
Commuting by train from Slough to central London, Sky News met 22-year-old Lauren Hughes for whom smartphone games are a great time-filler.
"I think there's a big kid in everyone, so I don't mind it," says Lauren.
"I also do things like the word games on there as well, Sudoku, Candy Crush - everyone does Candy Crush."
Unlike other types of computer gaming, such as those on consoles or multi-player internet based games, it is women who make up the largest number of people gaming on their mobiles.
Research by Mintel suggests that 13% of men and 6% of women confess to being "hardcore" gamers who are deeply involved in the gaming culture.
Twenty four per cent of men and 15% of women say they are moderate enthusiasts, classified as "regular" gamers.
But among "casual" gamers, such as those who play on mobile devices, 27% of women say they play versus 24% of men.
One of a growing community of women who are gaming enthusiasts is the New Statesman's Deputy Editor, Helen Lewis, who began playing in her childhood.
"Those big fighting, shooting games are blokey," says Helen. "Those are the ones that dominate the big blockbuster market.
"That's not the same when it comes to smartphone games which have a lot more puzzle based stuff, which are a lot more accessible to everyone.
"And what we've discovered with that is that there were a lot of women who wanted to play games, but just couldn't before and had we given them the chance before - who knows - many of them might have been playing for decades."
Regardless of the gender of players, the growing popularity of smartphones games has alarmed those who specialise in treating addiction to computer games and other forms of modern technology.
Dr Richard Graham of London's Nightingale Hospital told Sky News why these games can be addictive.
"Certainly, these games release chemicals within our brains that give us a sense of reward, of satisfaction, and often sort of a buzz of excitement.
"But the problem remains that when you switch off, you're depleted, downgraded and feel that you need to go back to do it again to get that same feeling of wellbeing."
The gaming industry in Britain alone is worth £1.7bn and with smartphones and tablets creeping into more of our lives they offer game developers another platform to sell their wares.
Dr Graham warned: "We're seeing a more casual, a sort of embedded use of games on mobile devices, such that whenever there's a spare moment someone might start playing a particular game.
"Most addiction patters are related to access. If we increase access to alcohol through licensing or pricing, one will start to see more problematic use and then, in turn, addiction.
"And I think understanding that smaller, intelligent, connected devices are increasing access to all sorts of platforms and games does increase the possibility of addiction."