Listening to the dulcet tones of Stephen Fry narrate JK Rowling’s Harry Potter And The Philosopher’s Stone might be very relaxing while you’re driving, but what about if you want to drift off into the land of nod – without worrying too much you’re missing out on vital plot points?

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Sleep Stories could be the answer – and they’re already proving really popular. The latest new feature of meditation app, Calm, the stories have been downloaded and listened to two million times in their first month.

They include Game of Thrones actor Jerome Flynn, reading A Magical Winter Night, a 19th century Eastern European folk story.

He says: “I’ll often wake up in the middle of the night, maybe for an hour or so when the worrisome mind can kick in; so, instead of just letting it worry or wander, I like to listen to stories or podcasts myself or do some mindfulness exercises.

“Now has become a really cool addition to my night-time options."

How stories get you off to sleep

One of the Sleep Stories is actually a talk on sleep science and advice by Dr Steve Orma, a clinical psychologist and specialist in treating sleep problems.

“There’s a paradox to sleep, in that it comes when you’re not trying”, he says. “When you try to sleep, your mind monitors your efforts, which then keeps you awake. Instead, have the intention of relaxing and letting go.

“The first step in getting a good night’s sleep is being in the right mindset. If you’re tired, relaxed and ready for sleep you will automatically fall asleep after 10 to 20 minutes. This is why doing something calming before bed will help prepare you for sleep.

This can be meditation, reading (nothing too exciting) or now listening to a ‘Sleep Story’, designed to help you let go and ease into a peaceful slumber.”

Calm co-founder Alex Tew adds: “Remember when you were young how much you enjoyed listening to a bedtime story? It was comforting, relaxing and soothing.

“When you’re a child, you have much less on your mind and sleep comes easily. Sleep Stories are meant to take you back to a simpler mental state and let your brain relax and prepare for a deep rest, just as it did when you were young. There’s no reason we can’t all have a good night’s sleep… without medication.”

[Read more: What is clean sleeping: Could it be 2017’s biggest health trend?]

The top 5 Sleep Stories:

These are the most popular ones on the Calm app:

1. The Waterfall - Fiction
2. Jupiter and his Mighty Company - Fiction
3. The Ocean’s Lullaby - Fiction
4. Silk Waves - Sleep Music - Fiction
5. Ferris Bueller's Teacher reads The Wealth of Nations by Adam Smith