By David Nield
We're celebrating the tenth anniversary of the first iPhone launch this year, so it seems an appropriate time to take a look back and how far we've come - and to review some of the very best mobile games that have appeared on iOS and Android in the last decade.
Picking an authoritative list of the 20 best games for just one year is an almost impossible task, let alone for a whole decade - there are just too many good ones to pick from - but these are the games we feel have helped to define smartphone gaming up to this point.
1. Fieldrunners (2008)
One of the earliest iOS games and one of the high watermarks for the tower defence genre - superb graphics, engaging gameplay, and plenty of clever variations to keep you coming back for more. Nowadays though, you're probably best playing the 2012 sequel instead.
3. Doodle Jump (2009)
Huge credit to the developers of Doodle Jump, who were some of the first to come up with a gaming formula that really worked on a small screen. If you've never played it, your character journeys up a sheet of paper, avoiding black holes and destroying baddies.
4. Words With Friends (2009)
Words With Friends took a familiar board game concept and turned it into a super-social mobile gaming experience that seemed to take over most of the civilised world back in 2009. It's no longer the force it was of course, but we've still got fond memories of it.
5. Canabalt (2009)
Maybe not the best endless runner ever but certainly one of the first to hit on a winning formula that others could follow. Canabalt is also a perfect example of how you don't need fantastically complex graphics to make a decent mobile game - it's all about the gameplay.
6. Fruit Ninja (2010)
Fruit Ninja was one of those games perfectly suited to mobile: simple but engaging gameplay, fast progressions, bright colours, loud sounds and lots of excitement. Even today, seven years after it was launched, it can hold its own against any other game.
7. Cut The Rope (2010)
Any mobile game could learn from Cut The Rope - it's incredibly easy (and fun) to get started, but then gets fiendishly difficult (and addictive) as you carry on. No wonder it was one of the first games to have a really huge impact on the fledgling App Store for iOS.
8. Temple Run (2011)
They're not, of course, the most complex of games, but Temple Run and its 2013 sequel are brilliant in their simple addictiveness, adding new tweaks to the well-worn endless runner formula to create something new. Mobile gaming would never be the same again.
9. Tiny Tower (2011)
You can find plenty of sim games for mobile - many are just crude adaptations of desktop titles - but Tiny Tower really takes the smartphone format and makes the most of it, hitting just the right balance of depth and simplicity, and running quietly in the background.
10. Draw Something (2012)
The popularity of Draw Something fell off very quickly, but there was a time when just about everyone was playing this - the Pictionary-with-friends app wasn't even a novel idea, but its blend of interactivity and competition made it a runaway success for a time.
11. Candy Crush Saga (2012)
If you've not lost hours of your life to Candy Crush Saga then you're (probably) in the minority, because mobile games don't get much more addictive than this. Match three coloured candles, build up your points, move through the levels and try and put it down.
12. Clash Of Clans (2012)
Likely to be instantly recognisable even if you've never actually played it, Clash Of Clans is a true blockbuster in the gaming world, downloaded hundreds of millions of times. Military multiplayer strategy at its finest and particularly well adapted for mobile devices.
13. Dots (2013)
In terms of mechanics and style - connecting coloured dots - this is one of the more original puzzle games to appear over the last decade, but it's similar to a lot of other games in our list in that it's easy to jump into, easy to learn, and very hard to master.
14. Threes (2014)
One of those mobile puzzle games that's very easy to get into and very difficult to put down, with the aim of the game to slide tiles around a board to make multiples of three. Like all the best phone games, Threes is fun and friendly too, and beautifully designed.
15. Monument Valley (2014)
One for fans of peaceful, contemplative puzzlers, Monument Valley raised the bar for visual style and ingenuity when it appeared in 2014: although many developers had tried something similar before, Monument Valley got it just right, and still hard to beat in 2017.
16. Crossy Road (2014)
Crossy Road ticks all the boxes for a superior mobile game, and it's no wonder it was one of Apple's favourites: mechanics that are clever but easy to understand, stylish visuals, just the right level of difficulty, and gameplay you can dip in and out of at any time.
17. Hitman Go (2014)
Hitman Go wasn't one of those smash hits that everyone was playing, but it's a perfect example of how to adapt a console video game for the smartphone - from level layouts to the input control system - and other big titles have since followed the same template.
18. Score! Hero (2015)
It's not fair to just choose one sports title but Score! Hero is a great example of how to adapt a sports game for mobile. Your football matches are broken down into passages of play and its down to the dexterity of your fingers and thumbs to get the ball in the net.
19. Alto's Adventure (2015)
Like a lot of the best mobile games, Alto's Adventure didn't do anything particularly new - it just brought gorgeous graphics, mesmerising music and gameplay that really ebbed and flowed in a natural way to an endless runner format that was looking on its last legs.
20. Pokémon Go (2016)
We're including Pokémon Go not because it was the most polished game ever released (it wasn't) but because few other titles have made such an impact in such a short space of time - for a while there, it seemed everyone was out on the streets catching Pokémon.