Effective date: September 3, 2026
PeriodVol (“the app”, “we”, “us”) is a menstrual volume tracker that estimates how much you bleed per day and per cycle, and predicts your next period, ovulation, and fertile window. This policy explains exactly what happens to your information. The honest summary is simple: everything you log stays on your own device. The only things the app ever sends are the anonymous, install-level usage ping and — if you opt in — the anonymous cycle summaries described below; neither contains your entries.
We do not collect personal information. PeriodVol has no user accounts, and the only thing our server ever receives is the anonymous, install-level usage ping and the opt-in cycle summaries described below — nothing that identifies you. The health information you enter — period days, flow volume and color, products used, clots, notes, and the dates we predict from them — is stored only on your device. It is never transmitted to us or to anyone else.
We do not ask for your name, email, phone number, or any account credentials. There is nothing to sign up for.
The installed iPhone/Android app checks whether a newer version of PeriodVol has been released, so it can show you an “update available” notice. To do that it downloads a small public file from periodvol.app that lists the current version number. This request contains none of your data — no health information, no identifier, no account, no cookie. It is the same kind of request your browser makes when loading any public web page, and like any web request our host briefly sees your IP address. Nothing is stored against you, and if the check fails the app simply carries on.
When the app starts, it also asks the App Store or Google Play for the current price of the optional one-time upgrade, and whether you already own it. That exchange happens between your phone and Apple or Google — it carries none of your entries, and we never see your payment details. We mention it because a network capture of the app will show it alongside the version check above, and we would rather list it than have you find it. One related note, for completeness: after you have logged a few days, the app may ask your phone to show its standard “rate this app” prompt. That prompt is drawn and handled entirely by iOS or Android — PeriodVol sends nothing and receives nothing, and none of your entries are involved. Your rating, if you leave one, goes to the App Store or Google Play, not to us.
Separately, opening a screen or taking an action — on the website or in the installed app — sends a small anonymous usage ping. Each ping says which screen or action it was, and carries a little context about the visit: how you got here (the site that linked you, and any campaign parameters on the link), your platform (iOS, Android or web), the app version, your display language, your device’s time zone, and its screen size. Pings from the app itself (the installed app, and the tracker page on the web) also carry a random install ID (a UUID generated on this install; you can reset it any time from Settings → Privacy → “Delete contributed data”). Pings from our other website pages — the landing page, the guides, the calculators — carry no ID at all, and no install ID is even created for them (this policy page sends no ping at all). The ID lets us count how many installs are active, tell pings from the same install apart, and see whether people come back. None of your entries — no health data, no dates, no volumes, no colours, no products — are ever included in a ping, and never will be; the code that sends it has no access to that data.
The actions counted this way are: the app opening, an entry editor being opened, an entry being saved, seeing a volume estimate, seeing the 80 ml heavy-bleeding notice, opening or printing the doctor report, seeing or dismissing the Pro screen, starting a purchase, completing a purchase, opening Settings, switching language, exporting a backup or spreadsheet, importing a backup, clearing all data, each step of the first-run intro, and turning the optional cycle-data setting on or off. On app open we also include how many days it has been since this install first ran and a rough band for how many entries have been saved on it (for example “6–20”) — never the entries themselves and never an exact count.
One event is deliberately left out of that tagging: ‘entry saved’ is counted without the install ID. Linking save times to a single install would produce a list of the days you logged on — and for a period app, that list is a cycle. We do not need it: how many entries an install has saved is already covered by the rough band above, so the exact days buy us nothing and we do not collect them.
Your entries are saved in your device’s local app storage (on-device database). This data stays on the device unless you choose to export a backup file and move it somewhere yourself. Uninstalling the app, or using “Clear all data” in Settings, removes the on-device data.
One honest exception worth naming: if you have your phone’s own device backup turned on (Apple iCloud Backup, or Google’s Android backup), your operating system may include PeriodVol’s on-device data in that encrypted backup — the same way it backs up your other apps. This is controlled entirely by your phone’s backup settings and goes to your personal Apple or Google account, encrypted by them; it never reaches us, and we have no access to it. If you would rather your cycle data was not included, you can exclude PeriodVol from device backups in your system settings (iOS: Settings → your name → iCloud → Manage Account Storage → Backups; Android: Settings → Google → Backup), or simply leave device backup off.
PeriodVol may ask for a couple of optional device permissions. Each is used only on your device and is entirely optional:
The Export feature lets you save a backup of your data as a file. Once you export a file, it leaves the app’s control and becomes your responsibility — for example if you save it to a cloud drive, email it to yourself, or move it to another device. We recommend keeping backups somewhere you trust. Importing a backup simply reads that file back into on-device storage.
The app contains no third-party tracking code or advertising SDKs. It contacts our own infrastructure only, for the requests described above — the update check, the store price check, the anonymous ping in §1b, and (if you opt in) the anonymous cycle summaries in “Anonymous cycle data (optional)”. Fonts and other assets are bundled into the app rather than loaded from external servers.
Because your entries live on your device and the only thing we hold is anonymous, install-level data you can delete from Settings, you are always in control:
Where laws such as the EU/UK GDPR, the Australian Privacy Act, or the California Consumer Privacy Act (CCPA/CPRA) apply, this on-device design is intended to honor their principles of data minimization and user control. We hold no personal data about you: your entries never leave your device, and the anonymous usage pings and opt-in cycle summaries carry at most a random install ID that we cannot link to a person — we treat that data as pseudonymous and never attempt to re-identify anyone. You can stop it at any time by turning the setting off, and delete what was sent from Settings → Privacy → “Delete contributed data”. Resetting your install ID also clears the two counters the app keeps for this purpose (when it first ran, and how many entries have been saved), so a reset really does start over.
PeriodVol is intended for people who menstruate and is not directed at children under 13 (or the minimum age in your country). We do not knowingly collect personal data from anyone, and the anonymous, install-level data described above never includes age, name, or anything else that could identify a person.
The information you track is sensitive reproductive-health data, which is exactly why PeriodVol is built to keep it on your device only. PeriodVol is not a medical device. Volume figures are estimates, and predicted dates (period, ovulation, fertile window) are estimates that may be inaccurate and must not be used as a method of contraception. Consult a healthcare professional for medical advice.
Off by default. If you turn on “Contribute anonymous cycle data” in Settings → Privacy (or say yes when the app asks after your first completed cycle), the app sends one line per finished cycle: its total estimated volume rounded to 5 ml, how many days it lasted, the number of days since your previous cycle started, the month it started, your app language, platform (iOS / Android / web) and app version — tagged with the same random install ID as the usage ping. Cycles still in progress are never sent.
What is never sent: dates, your daily entries, which products you used, clots, flooding, your name, email or location. We never store your IP address. The server cannot work out which days your period fell on.
Why: real-world period-volume data does not exist outside a few clinical studies. Aggregated, anonymous summaries let us publish reference ranges and improve the app’s estimates. We only ever use this data in aggregate.
Your control: switch it off any time (nothing further is sent). “Delete contributed data” removes every row sent from this install and resets the install ID, so past data can no longer be linked to future pings. Because the rows carry a pseudonymous install ID, we treat them as pseudonymous data and never attempt to re-identify anyone.
If we change this policy, we will update the “Effective date” above and post the new version here. The optional anonymous cycle data described above is the only such feature today; it is off by default and asks for your consent in the app. If we ever add another feature that sends data off the device (for example an encrypted sync you choose to enable), we will describe it here and ask first.
Questions about this policy or your privacy? Email privacy@periodvol.app.