Sumbi - Focus & Digital Detox
Phone down, life gets deeper
Only for iPhone
Free
iPhone
The first sea opened in September 2026.
Set a dive time and put your phone down and a haenyeo dives into the sea.
The longer you stay the rarer the creatures you meet.
The longer your phone rests, the deeper life becomes.
Sumbi turns the time you spend away from your phone into a haenyeo's dive.
Haenyeo are the free-diving sea women of Jeju, Korea, and this whole app grew out of their culture.
■ You choose just two things
Dive time, and breathing room.
Breathing room is how long you're allowed to use other apps mid-dive, anywhere from 0 to 60 seconds.
Use it all and the haenyeo runs out of breath, surfaces, and that dive ends there.
Phone calls are okay. Finish the call, come back, and your dive continues.
■ Stay deeper, meet rarer creatures
Hold on until the end and a shell will be waiting on the seafloor.
Open it and you meet a creature.
Clownfish live in the shallows.
Green sea turtles swim further down. And if you go deep enough, aurora jellyfish drift through the abyss.
The longer the dive, the deeper the sea you reach.
■ An ocean to tend, not a collection to finish
The creatures you meet live on in your ocean.
Meet the same kind again and they school together.
When the sea gets full, you release someone back to the open water.
There are no numbers or stats on this screen.
It's made for gazing. And even after you let a creature go, the record of that meeting stays forever.
■ The sea is fair
Money doesn't buy the odds here. Neither do settings or friends.
The only thing that moves the probability is time spent in the sea.
The chance of meeting an abyssal creature never goes above 8% on any dive, and that number is published as-is inside the app.
There are no subscriptions and no loot boxes.
If a creature wins you over, you can invite it for a small one-time price, and it's yours for good.
■ It's okay to fail
No dying trees. No red warnings.
"You surfaced a little early. Your time in the sea is kept in your log."
That's the whole message. Catch your breath and dive again.
■ You don't have to dive alone
Link up with one person you trust and you'll get each other's dive news.
Your buddy isn't there to watch you. They dive with you.
■ The night sea has a different face
Start a dive between 9 p.m. and 6 a.m. and you'll meet different creatures, because some of them only wake at night.
The abyss, though, is always night.
■ A log that reads like a diary
No scores, no rankings, no week-over-week charts.
Just the day's dive and the creatures you met that day, written down quietly.
■ Born from Jeju haenyeo culture
When a haenyeo surfaces after a dive, she lets out one long whistling breath called the sumbisori.
That sound gave this app its name.
A haenyeo stays in the sea only as long as her breath allows, and Sumbi was built the same way.
The Culture of Jeju Haenyeo was inscribed by UNESCO as Intangible Cultural Heritage in 2016.
You can read the full story at https://sumbi.app
Sumbi measures success by the time you don't spend in the app.
Contact: sumbi@niceday.io
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The developer, 나이스데이, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
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Information
- Seller
- niceday Co.,Ltd.
- Size
- 90.9 MB
- Category
- Productivity
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later.
- iPhone
- Languages
English and 2 more
- English, Japanese, Korean
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- Copyright
- © 2026 sumbi. niceday Inc.