Applications for smartphones running the Google Android OS have really come into their own this year.
Most of the apps that Google showcased last year in its first Android Developer Challenge were relatively simple location-based services that relied upon Android's Google Maps programme.
However, this year's Android Developer Challenge showed off an enormous variety of complex applications that let users play guitar, learn about astronomy, get information on famous art or even chase down ghosts.
We've picked out some of the coolest apps from this year's Android Developer Challenge, whether they're games, reference apps or productivity tools.
One of the more irritating features in modern life comes whenever you nod off to sleep only to be rudely awakened by a late-night phone call.
SweetDreams fixes this by letting you actively manage your phone's behaviour for night-time hours, from disabling sounds for texts and phone calls while directing calls straight to your voice mail.
The best part about the app is that you only need to apply the settings once and then you never have to worry about having your slumber disturbed again.
Created by Spanish developer Inizziativa, this app won't be available on the Android market until next year.
What the Doodle!?
Price: $1.00 (61p)
Ah, Pictionary. The classic party game that's uniquely humiliating for people who can't draw such seemingly simple objects as fire hydrants or binoculars.
And now people can share their lack of artistic ability with the whole world by using What the Doodle!?, a real-time online game in which users draw pictures of objects on their phones' touchscreens while other users try to guess what they are.
And you thought it was tough drawing puppies with a magic marker on a white board!
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