They're an indispensable part of owning a smartphone - mini pieces of software that have changed the way we live our lives and do our work.
Apple once coined the phrase "There's an app for that" but even it could never have predicted how quickly and pervasively the format would catch on.
Today there are nearly 1.4 million apps available across the two major platforms of the Apple iOS App Store and Android's Google Play.
It's a number that dwarfs their nearest competitors - the Windows Phone Store and BlackBerry App World - which contain just a couple of hundred thousand between them - although both are set to launch new operating systems in the coming months to harness the power of apps more deeply.
But where is that "next big thing" coming from? This week app developers gathered in London for the AppsWorld exhibition to try and find out.
[Related: Facebook hits 1 billion users worldwide]
From augmented sound to mobile payments, the race for control of our fingertips is on.
Trevor Klein, head of development at Somethin' Else, said future success rests on an app's ability to interact with real objects in the real world.
He explained: "There will be lots more interaction with objects in the physical world and there is currently a whole load of experimentation around innovative hardware that connects with apps to make your life easier or more informed.
"Things like Lockitron, which monitors when your front door is locked and unlocked and let's you open it remotely, along with smart meters for your electricity or the app to turn on your central heating while out of the house that British Gas is trialling.
"People with long-term health conditions will also have the tools to monitor and react in real time to what's going on in their bodies. All of this is happening now, but will start to go a lot more mainstream."
He added: "There will be increasing use of voice and gesture input using cameras and microphones, you won't need an Xbox 360 accessory such as Kinect or specialist hardware, it'll all be in your phone and in many cases it already is.
"There will also be more augmented sound. We're doing a lot of work in this area and it is still chronically underused in the visual-obsessed world of apps.
"What augmented reality is doing for video, overlaying signs or animations onto the real world when looking through the device's camera, is starting to happen with audio.
"It will become increasingly information-based so with your headphones on, you get turn-by-turn directions or vocal notifications such as when you're walking past a bar and it says 'your friend checked in there five minutes ago. He might still be there. Why not go have a look?'."
Running app VIA which provides directions while you run is exploring adding augmented sound in the next version. Its creator Olly Joshi said: "Augmented sound has massive potential for the future of apps. Combining an element of new sounds that complements or surprise a user's environment can bring a totally new experience.
"The new VIA running app is unique in allowing people to listen to music whilst being given voice directions. If they go off track it automatically updates with new directions and we're already looking at how augmented sound could further that."
The apps business is now worth billions of pounds so finding the next big thing can be hugely financially rewarding. After all, it wasn't so long ago that a simple game about Angry Birds and pigs generated millions of pounds in sales from hundreds of millions of downloads.
However, even niche apps with a popularity of only a few thousand people can be life-changing even if they don't generate big bucks.
Brands big and small are desperate to increase their customer base and sales through apps, competing with the bedroom creators looking to sell on their idea for millions.
Governments and public bodies have joined the app race too to provide easier access to national services and make UK-wide data more readily available to anyone who wants it with information-based apps, especially through augmented reality viewing, predicted to form a large part of the next incoming wave.
Gary Gallagher, of developers Paper Bag, believes the time is nigh for smartphone software that simply apes a website or fails to provide interaction for the user.
He said: "Augmented reality and image recognition is an area moving really fast. Aurasma are making interesting things with some powerful case studies of interaction.
"NFC and the mobile wallet is also interesting, but only if Apple decide to get in the mix and support it with the technology on their phones.
"The apps world is an extremely competitive space. So to stand out from the crowd you have to offer a product or service that is different. Customer-facing/marketing apps can have a very limited shelf life."
One app aiming to break that mould has stolen the headlines this week with Wonderbra announcing an augmented reality app that strips a model of her clothes, revealing her underwear.
Crowd-funding is another area that is changing the way apps are created. Sites like Kickstarter and more focused app ones like Appbackr and Appslit offer the chance for anyone to get the cash to fuel their app idea - as long as it resonates with those who'll be using it.
They're already filled with projects including many which have successfully closed deals for anything from a few hundred to a few thousand pounds.
Mike Anderson, CEO of Chelsea Apps Factory, believes the Government has a part to play in helping find the "next big thing".
He said: "AppsWorld was twice as big as last year with significant players like RIM, Windows and Android there along with senior executives from lots of FTSE 250 companies. Everyone is now interested in apps.
"The Government should be getting behind helping British companies employ young people to develop these things. We have the talent and British businesses will support British development if they can get the quality product."
Somethin' Else's Mr Klein believes the future of apps however lie as much in the "next big thing" for the hardware as the software.
He said: "I'm watching to see what happens after Christmas this year in the UK with sales of the various Kindle Fires and whether consumers start buying a lot of apps on them rather than content like films and books.
"I'm also betting the Windows 8 ecosystem will make big inroads with first time smartphone and tablet owners for business especially and will shake up, but not topple, the Android/iOS dominance for everyone else."
Available to pre-order now in America, with shipping expected in March next year, this £100 device attracted six times as much crowd-funding as it needed. Install it on a door and you can lock or unlock it through a smartphone app and it'll also save that age-old problem of worrying whether you actually locked the door when you went out in the morning. You can also instantly give access to friends and family.
Shown off to gasps of excitement at the Apple iPhone 5 launch, years of research at Oxford University have gone in to creating this "virtual friend". You must train the fella up and teach him new ninja skills with makers NaturalMotion saying he's the first "artificial intelligence" character that uses real-time simulations of the body and nervous system, which previously would have needed a supercomputer to work.
This iPhone running app claims to be the first map-based training solution that provides step-by-step audio directions through your headphones as you pound the streets, eliminating the need to look at your handset and risk tripping or hitting a lamppost. Its makers are working on ways to incorporate augmented sound into the next version - perhaps they could include a prompt when you pass a toilet.
The winner of Startup App 2012 at this week's Appsters Awards works with Spotify to allow you to listen to music socially, at exactly the same time as friends, wherever you all are. You can then vote for your favourite tracks and chat about what you've been hearing. It won't make your music taste sound any better but at least you'll be able to talk about it with like-minded 'individuals'.
While not to everyone's taste, this just-launched app shows some of the power and possibilities of augmented reality for objects around us and the brands we buy and love. Hold your smartphone camera over pictures of models found online and in magazines and a special code inserted into the image will cause the lady's clothes to disappear, revealing her underwear.