Track your cycle. Keep your data. No ads.
A serene, offline-first menstrual cycle tracker built for privacy.
100% Private
Your data never leaves your device unless you choose to sync it to your private Google Drive. Zero telemetry.
Calm & Minimal
Just the tracker. No forums, no ads, no unsolicited predictions.
Always Offline
Works perfectly on airplane mode or in low-signal areas.
Questions
Is VampirApp free?
Yes. VampirApp is a free period and cycle tracker with no ads, no subscriptions and no in-app purchases.
Where is my data stored?
On your device, in your browser. There is no VampirApp server, no analytics and no trackers, so we never see your logs.
Do I need an account?
No. If you want a backup or to use several devices, you can sign in with Google. Your data is then stored in a hidden app folder in your own Google Drive that only VampirApp can access.
Does it work offline?
Yes. Once loaded, the app works without an internet connection. If Google Drive backup is on, your changes sync when you are back online.
How does it predict my next period?
It adds the cycle length you set in Settings to the start of your last period, and marks that day and the day before.
Can I use it as contraception?
No. VampirApp is not a medical device and predictions are estimates. Do not use it to plan or avoid pregnancy.
How do I install it on my phone?
Open vampir.app in your phone’s browser and add it to your Home Screen. Settings shows the steps for your device.