The short version
HydraCal does not collect your data. Everything you record stays on your iPhone or iPad. The app has no user accounts, no servers, no analytics, no advertising and no third-party tracking. It does not send anything anywhere — the app contains no code that transmits information over the internet.
The only time your information leaves your device is when you choose to export, print or back it up, and then it goes only where you send it.
1. Who we are
HydraCal is published by Defender Days Ltd ("we", "us"), a company registered in England and Wales. If you have a question about this policy, please use the contact form.
This policy covers both the HydraCal app and this website. They are treated separately below, because they behave differently: the app collects nothing at all, while the website collects only what you choose to type into the contact form.
2. What HydraCal stores
HydraCal is a personal record-keeping app. To do its job it stores the following on your device only:
| What | Why |
|---|---|
| Nutritional supplement entries (Fortisip, Calogen, Vital), including the number of servings and the time you recorded them | To total your daily fluid and calorie intake |
| Feeding tube flushes and other drinks, with volumes and times | To total your daily fluid intake |
| Any other calories you record, with your own description | To total your daily calorie intake |
| Your daily fluid and calorie targets | To show progress against your goals |
| Your reminder times and days | To schedule local notifications, if you turn them on |
| The date and time you last used the app | To roll over to a new day correctly |
This information is health-related, and we treat it accordingly — which is why none of it is sent to us or to anyone else.
Where it is stored
The data is held in HydraCal's own storage area on your device, which other apps cannot read. It is protected by your device's own security: if your device is locked with a passcode, Face ID or Touch ID, iOS encrypts app data at rest.
If you use iCloud Backup or back up your device to a computer, your HydraCal data may be included in that backup. Those backups are controlled by Apple and by your own settings, not by us. Apple's handling of them is covered by Apple's privacy policy.
3. What HydraCal does not do
- No accounts. You never create a login, and we never ask for your name, email address, date of birth or any other identifying detail.
- No servers. We do not operate a back end for this app. There is nowhere for your data to be sent.
- No analytics or crash reporting. We do not measure how you use the app.
- No advertising, and no advertising identifiers.
- No tracking across apps or websites, and no data sold or shared with data brokers.
- No third-party SDKs that collect information.
- No location, camera, microphone, contacts, photos, calendar or health-app access. HydraCal does not request any of these.
4. When your information leaves your device
Only when you choose to send it. HydraCal lets you:
- Export your history as a spreadsheet or summary file;
- Print or produce a report to share with your dietitian, nurse or doctor;
- Back up your data to a file, and restore it later.
Each of these is something you start yourself. When you do, iOS hands the file to whichever app or destination you pick — email, Files, AirDrop, a printer, a messaging app. From that point the file is in your hands, and how it is stored or transmitted is governed by whatever service you chose. We never see it.
Because these files contain health information, please think about where you are sending them, particularly over email or messaging apps.
5. Notifications
If you turn on reminders, HydraCal schedules them locally on your device using iOS's own notification system. They are not sent from a server, and they contain only a general prompt to check your intake — never any of your recorded figures. You can turn reminders off inside the app, or revoke the permission entirely in your device's Settings.
6. Deleting your data
You can remove individual entries in the app at any time. To delete everything, delete HydraCal from your device — iOS removes the app's stored data with it. Bear in mind that a device backup made before you deleted the app may still contain the data; managing those backups is done through your device settings or iCloud.
We cannot delete your data for you, because we never have it.
7. Your rights under UK data protection law
UK GDPR gives you rights over personal data that an organisation holds about you — to access it, correct it, delete it, or object to how it is used.
Those rights are exercised against whoever holds the data. In HydraCal's case, Defender Days Ltd holds none of it: the app collects nothing and transmits nothing, so we are not a controller or processor of anything you record. Your data is under your control, on your device, and you can view, amend, export or erase it yourself at any time.
The one exception is the contact form on this website: if you use it, we hold what you sent in order to reply. See section 8. You can ask us to delete that correspondence at any time.
8. This website
The website carries no analytics, no advertising, no tracking pixels and no third-party embeds. It sets no cookies, which is why you have not been asked to accept any. Simply reading these pages tells us nothing about you beyond the standard access logs our hosting provider keeps for security and diagnostics.
The contact form
If you choose to use the contact form, that is the one place on this site where you give us information. It sends us:
- the name and email address you enter;
- the topic you select and the message you write.
The message is delivered to our inbox using Resend, an email delivery service acting as our processor. We use what you send only to reply to you, and we keep the correspondence only for as long as it takes to deal with your query. We do not add you to any mailing list, because there isn't one.
Please do not put medical details into the form that you would not want to send by ordinary email. A description of the problem is enough, and we would rather you told your healthcare team than us.
9. Children
HydraCal is intended for adults managing their own nutritional intake, or for a parent or carer recording intake on someone else's behalf. It is not directed at children, and it collects no information from anyone. If a child uses the app, everything recorded stays on that device in the same way.
10. Changes to this policy
If HydraCal ever changes in a way that affects your privacy — for example if a future version were to add an optional cloud backup — we will update this policy and change the date at the top before that version is released. We will not start collecting anything without saying so here first.
11. Contact
Questions, corrections or concerns: please use the contact form.
If you are in the UK and are unhappy with how we have handled a data protection matter, you can complain to the Information Commissioner's Office at ico.org.uk.