Ozvenka: Echo Deduction
Listen. Deduce. Never guess.
Free · Designed for iPad. Not verified for macOS.
A dark cave, stones you never see, and an echo that gives them away. 120 caves, plus one daily cave that is the same for everyone. No ads, no internet.
Ozvenka is a quiet logic puzzle about listening.
The cave is dark. Stones lie somewhere inside it and you will never see them. You put nothing into the cave — you send an echo in from the edge and listen for where it comes out. Either it appears somewhere else, or a stone swallows it, or it returns the way it went. From what you hear, where the stones lie can be worked out. Not guessed. Worked out.
• 120 caves across ten worlds, plus a daily cave — one a day, the same one for everyone
• Every cave's par is the smallest possible number of echoes. It is not the author's estimate: the same solver that verified the cave computes it
• You never have to guess: every cave has exactly one answer, and the echoes can always settle it
• When you get it wrong, the game says why: whether an echo contradicts your reading, or whether you simply have not heard enough yet
• The hint is computed from what you have actually heard. It never points at something that is not in the cave
• Once you solve it, you see where the echoes really went
• Slovak, English and Czech
No ads. No in-app purchases. No accounts, no sign-in.
And no internet: every cave and every daily is inside the app, so it plays on a plane. Nothing about you is collected or sent anywhere — the statistics stay on your phone.
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The developer, Web 3.0 s.r.o., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
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Information
- Seller
- Web 3.0 s.r.o.
- Size
- 1.9 MB
- Category
- Puzzle
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Drozd Studios