There’s an app for tracking sleep and one for tracking your run in the forest. There’s one for meditation and breathing and eating. It's your tool at work and when doing banking matters, food orders, shopping and ordering cabs . You socialize on it, share moments with family and friends or strangers you fancy. Dating, playing games, dancing, listening to books, exercising, writing - there’s one for all. They make our lives easier. But there’s also a backside.