Terms of use
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This app does not predict fish. It models the physics of light and contrast underwater, and tells you how much a lure stands out from the water. That is a real, measurable quantity, and it is a necessary condition for a fish to notice your lure — but it is not a sufficient one, and nothing here is a promise of a catch.
What you are getting
A calculator. It takes a lure colour, a depth, a water type, a light condition and a target species, and estimates apparent contrast and detection distance from published optics and published fish physiology. Every figure it uses is cited, and every place where the evidence is thin is labelled as such inside the app rather than hidden.
Accuracy, and its limits
- Water types are classes, not measurements of your lake. Two waters that both reasonably answer to "slightly stained" can differ by a third in their actual attenuation.
- Most species have never had their visual pigments measured. Where that is the case the app says so, in the species card, in the strongest terms available.
- Several parts of the model are declared assumptions rather than measurements — the fluorescence quantum yield in particular. They are listed openly in the method notes.
- The app does not model polarisation, motion, vibration, the lateral line, or anything at all about behaviour.
No regulatory or safety advice
Nothing in this app or on this site is advice about fishing regulations. Size limits, closed seasons, protected species, licences and quotas vary by region and change without notice. Check with your local authority. Nothing here is advice about safety on or near water either.
Purchases
Payment is handled by Apple or Google, never by us. There are two paid options and they work differently, so both are spelled out:
- Premium — €4.99 a year, a subscription. It unlocks every species, including species added after you subscribe, for as long as the subscription is active. It renews automatically every year until you cancel. You cancel it in the store you bought it from, not in the app: on Android that is your Google Play account, on iPhone and iPad it is your Apple Account in Settings. If you let it lapse, the species catalogue locks again — nothing you bought outright is affected.
- A single species — a one-time payment. It unlocks that one species permanently. It does not renew and it is not part of the subscription.
Prices are shown in your own currency, inclusive of local tax, by the store — the figures above are the euro price and yours may differ.
Refunds are handled by the store you bought from, under its policy, not by us.
If you bought Premium before it became a subscription
Premium was originally sold as a single permanent payment. If that is what you bought, it still unlocks everything, permanently, and you will never be asked to subscribe. Changing what we sell is not a reason to take back something already paid for.
Unlock codes
The app accepts an unlock code, entered on the same screen the paid options appear on. A valid code unlocks the whole species catalogue permanently, at no charge — it is not a purchase, nothing is billed, there is nothing to renew and nothing to cancel. Codes are issued by us; we can stop issuing new ones at any time, and a code already redeemed keeps working.
The rewarded-ad unlock is temporary
You can also unlock a single species by choosing to watch an ad. That unlock lasts 24 hours and then expires. It is not a purchase, you are not charged, and nothing is refundable because nothing was paid.
Watching another ad for the same species restarts the 24 hours rather than adding to it. This term is stated on the button itself in the app, in a note under it, and again on the species card while the unlock is running — because it is exactly the kind of term that is unfair to bury.
What is always free
Every water type, every depth, every light condition and every viewing geometry is free and complete for everyone, permanently. The physics is not behind the paywall and will not be put there. Only the species catalogue is paid.
Acceptable use
Personal use. Do not redistribute the app's data as your own, and do not present its output as a guarantee of anything to anyone else.
Liability
The app is provided as is. To the extent the law allows, we are not liable for decisions made using it — including a blank day. Nothing in these terms removes any statutory right you have as a consumer.
Changes
If these terms change, the date above changes with them in the same release.
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