rather than laptops, to socialise online with friends. This creates two important factors to consider when building an app: speed, which we will look at later, and social connectivity. Whatever you do, make sure an app allows users to interact with each other. Be this via Game Centre, Twitter or Facebook. Friends need to be able to compete or share. "There is also a real premium on social. The phone is by nature a social device, sometimes you make phone calls and send text messages to friends," says Decrem. "People enjoy using these devices to communicate with friends." Consumability An app is a disposable thing. Very few last beyond a day or two's play on your smartphone. Cheap and easily ignored, for an app to do well it needs to grab the attention of a phone-user for just long enough to justify its cost. We aren't saying cut corners with your application, more to understand that its vitality and sales won't necessarily come from its length or complexity. "Apps are consumable. They are more like YouTube videos than a console game. Ninety-nine per cent of apps, you use them once or a day or two and then you get rid of them," says Decrem. This relates directly to how an application will spread through the App Store. Unlike most technology, which is promoted via advertising, the app gains sales traction from word of mouth. "These things spread increasingly quickly as a result of word of mouth. This is the primary