Slumber is a free-to-use app designed to help you fall asleep quickly and beat insomnia. The app offers a collection of ultra-relaxing sleep-inducing stories and meditations to help you turn off your mind and enter a state of deep calm. Slumber is equipped with a large library of sleep meditations, bedtime stories for kids, and ASMR soundscapes. The meditation guides and storytellers use mindfulness, gratitude, and suggestive hypnosis to help you relax and fall asleep. The app also offers customizable nature sounds, delayed ending, and offline listening. You can track your usage and sleep quality over time and sync your meditations with Apple Health's mindfulness minutes via HealthKit.

The app is highly rated and has received positive reviews from various sources such as The Wall Street Journal, Forbes, and Lifehack. Users have also praised the app for its effectiveness in helping them fall asleep quickly. However, the app offers an auto-renewing subscription, which may not be suitable for all users.

Overall, Slumber is an excellent app for anyone who struggles with insomnia and wants to improve their sleep quality.