Comparison

WHOeyes vs Clio Daye

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

WHOeyes

This application offers a free vision screening tool to help identify potential vision impairments. It simulates standard eye chart tests for both distance and near vision, suitable for users aged 8 and above. Regular use can aid in early detection, encouraging timely professional eye care.

Highlights
  • Distance vision test
  • Near vision test
  • Simulates eye chart
  • Suitable for ages 8+
  • Free to use
Read full description

Many people with vision loss are unaware of it. Regular vision checks can ensure that vision impairment is identified at the earliest so that you can take action to continue enjoying your sight. WHOeyes is a free mobile application that tests distance and near visual acuity and is suitable for anyone aged over 8 years. The principle of WHOeyes is based on how an eye care professional would test your vision using a conventional chart in a clinical setting. The accuracy of WHOeyes was tested in two research studies. The app does not replace the need for regular eye checks by an eye care professional, even if your vision is good. WHO and the developers of the app cannot be held responsible or liable for any incorrect results. WHOeyes is compatible with iPhone 8 and above. To find out more about eye care and access related resources, visit the webpage at: https://www.who.int/health-topics/blindness-and-vision-loss.

About

Clio Daye

Features
Read full description

Your cycle data is yours. We mean that literally. Most period tracking apps are free because they make money from your data. That data gets sold to advertisers, shared with data brokers, and in some US states has been requested by law enforcement. We found this unacceptable. So we built Clio Daye. Everything you track in Clio Daye lives only on your device. There is no account to create, no server receiving your data, no cloud backup, no subscription, no ads. We have no access to your data. Nobody does except you. That was the whole reason we built this. How it works Clio Daye covers the things that matter in day-to-day cycle tracking. You can log flow intensity, 15 different symptoms, mood, and notes. It shows your current cycle phase and predicts when your next period is likely to start, with an honest uncertainty range rather than a false-precision date. Over time, it surfaces patterns in your flow, symptoms, and mood so you can see what your own cycle actually looks like. Most apps tell you when your next period is due. Clio Daye shows you a rolling six-month picture of your cycle so you can plan ahead, not just react. Useful for travel, events, or simply knowing what kind of week you're heading into. Everything is protected by Face ID, Touch ID, or a PIN. If someone else picks up your phone, they cannot open the app without your permission. Who it's for Anyone who has a menstrual cycle. Clio Daye uses body-neutral language and doesn't assume gender. It's designed for people across all life stages, from first cycles through perimenopause. A lot of people who try Clio Daye have already had a bad experience with another app. Maybe you found out your previous app shared your data in ways you never agreed to. We built this for exactly that reason. Open source and free, forever Clio Daye is free with no subscription, no premium tier, and no advertising. The source code is public at github.com/pjaol/safeflow so anyone can read it and verify the privacy claims for themselves. We're not a venture-backed startup optimizing for growth. We're a small team who thought this tool should exist and built it. A note on what this isn't Clio Daye is not a contraceptive tool and should not be used as one. Predictions are estimates based on your logged history and become more accurate as you log more cycles. If you need contraception or have medical concerns about your cycle, please talk to a healthcare provider. Requires iOS 17.5 or later.

Screenshots

WHOeyes4 screens
Clio Daye3 screens

Verdict

The call

The clearest difference is update cadence: Clio Daye at every 11 days against WHOeyes's every 6 months. WHOeyes's advantage is device support (3 vs 1) and iOS requirement (15.6 vs 26.0). On price, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

WHOeyes ships an update every 6 months, Clio Daye every 11 days. The most recent releases landed on November 3, 2026 and October 25, 2026 respectively.

Scorecard3 real differences · 6 level
WHOeyes versus Clio Daye: the parameters behind the verdict, then further details
ParameterWHOeyesClio Daye
PriceFreeFree
Rating1.7 (3 ratings) — better—
Number of ratings3 — better—
Update frequencyEvery 6 monthsEvery 11 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.6 — better26.0
Further details — not scored
Size18 MB4 MB
Age rating12+4+
DeveloperWorld Health Organizationpatrick o'leary

In-app purchases

None

WHOeyes

No in-app purchases

None

Clio Daye

No in-app purchases

Questions

Is WHOeyes free?
WHOeyes is free to download, with no in-app purchases.
Is Clio Daye free?
Clio Daye is free to download, with no in-app purchases.
Do WHOeyes or Clio Daye have ads?
Neither WHOeyes nor Clio Daye shows ads.
Which is updated more often, WHOeyes or Clio Daye?
WHOeyes ships an update every 6 months, and Clio Daye every 11 days. Most recently, WHOeyes was updated on November 3, 2026 and Clio Daye on October 25, 2026.

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