The Most Private Period Tracker App
Your reproductive health data is deeply personal. Eve Day keeps it that way with 100% on-device storage, no cloud sync, and no data collection - ever.
Your reproductive health data is deeply personal. Eve Day keeps it that way with 100% on-device storage, no cloud sync, and no data collection - ever.
In an era of data breaches, targeted advertising, and concerns about how health data might be used, privacy isn't just a feature - it's a necessity. Period and fertility tracking data reveals intimate details about your health, relationships, and life choices.
Many popular period tracking apps collect your data, store it on their servers, and share it with third parties for advertising, research, or other purposes. Some apps have been caught selling user data without consent. Others have had data breaches exposing sensitive health information.
Eve Day takes a fundamentally different approach: we never collect your data in the first place. What we don't have, we can't lose, sell, or be compelled to hand over.
With Eve Day, you can track your most personal health data without worrying about who might access it. Your period history, fertility signs, symptoms, and health conditions are yours alone.
All your data is stored locally on your iPhone using Apple's SwiftData framework. Your period dates, symptoms, fertility signs, pain levels, medications - everything stays on your device. There is no cloud database, no server, no backup system on our end. We literally cannot see your data.
Eve Day doesn't require you to create an account, sign in with email, or connect any social accounts. There's no username, no password, no email verification. Just download and start tracking - anonymously.
Eve Day works completely offline. You never need an internet connection to log your period, view your calendar, check predictions, or access any feature. The app functions fully in airplane mode.
We don't use analytics SDKs like Google Analytics, Firebase, or Mixpanel. We don't track which screens you visit, how long you use the app, or what features you use. We have no insight into your behavior within the app.
Eve Day doesn't include advertising SDKs, social media integrations, or third-party services that could collect your data. The app contains only the code we wrote and Apple's standard iOS frameworks.
Eve Day is completely ad-free. No banner ads, no video ads, no sponsored content. This means no ad networks tracking you, no behavioral targeting, and no data sharing with advertisers.
Many apps claim to offer AI features while secretly sending your data to cloud servers for processing. Eve Day is different - our AI runs entirely on your iPhone.
Eve Day's pain predictions, pattern recognition, and personalized insights are powered by Core ML models that run locally on your device. Your health data never leaves your phone for AI processing.
As you log more data, Eve Day's AI learns your patterns and improves predictions. This learning happens entirely on your device. We don't receive your data, and we don't send back updated models. Everything stays local.
Eve Day doesn't use cloud AI services like OpenAI, Google Cloud AI, or AWS Machine Learning. We built our own lightweight models that run efficiently on iPhone hardware without any network connection.
Eve Day shows you exactly what the AI has learned about your patterns. Our "What Eve Has Learned" feature lets you see the factors influencing your predictions, so you understand how the AI works with your data.
Let's be explicit about what Eve Day never collects:
This isn't a policy that could change - it's baked into our architecture. Eve Day has no server infrastructure to receive your data. We couldn't collect it even if we wanted to.
Not all period trackers treat your privacy equally. Here's how Eve Day differs from typical period tracking apps:
| Feature | Eve Day | Typical Apps |
|---|---|---|
| Data storage | On your device only | Their cloud servers |
| Account required | No | Yes (email/social) |
| Works offline | Yes, fully | Limited or no |
| AI processing | On device | Cloud servers |
| Analytics tracking | None | Extensive |
| Third-party sharing | Never | Common |
| Advertising | None | Targeted ads |
While we don't collect your data, you have complete control over what's on your device.
Export all your cycle data, symptoms, and AI model information anytime. Take your data with you if you switch apps or want a backup. Your data belongs to you.
Generate PDF reports to share with your healthcare provider when YOU choose. These reports are created locally and only shared if you explicitly send them.
If you want, you can connect Eve Day to Apple HealthKit to sync data with the Health app. This stays entirely within Apple's ecosystem on your device - we never access HealthKit data ourselves.
Delete the app and all your data is gone. No residual data on our servers (because there are no servers), no account to delete, no "we retain data for X days" policies. It's simply gone.
Our privacy policy is short, clear, and human-readable because we don't do much - by design. There's no complex legalese about data sharing because we don't share data. There are no opt-out procedures because there's nothing to opt out of.
Eve Day wasn't retrofitted for privacy - it was built from the ground up with privacy as a core requirement. We believe you shouldn't have to choose between powerful health tracking and protecting your personal data.
Free, private, and yours alone.