How Calm is using machine learning to keep us all mellow Read later Audio version (Image sourced via Calm) With a mission is to make the world "happier and healthier" by helping people prioritise mental health and claiming to be the world's most popular sleep, meditation and relaxation app Calm exults in being what the Centre for Humane Technology dubs "the world's happiest app". Designed to help users manage stress, sleep better and live a happier, healthier life, the app is available in more than 190 countries. But for all the apparent talk of "calm science," there's a lot of deep IT and data-driven marketing behind the way the privately held, nine-year-old company gets such high satisfaction rates for its meditation app.