fisheggs

Availability does not collect anything about you.

There is no account to make, no server to sign in to, and the app does not send anything over the internet. If you put your phone in aeroplane mode the app works exactly as it did before.

Your calendar

The app reads the calendars on your phone to work out which days you are free. It reads them while it is open, holds what it finds in memory, and forgets it when it closes. Your appointments are not copied into the app's own storage, and none of it is sent anywhere.

The app only reads. It never creates, changes or deletes an appointment.

iOS does not offer a read-only calendar permission. The choices Apple gives an app are "add to your calendar" or "full access", and full access is the only one that allows reading. So the app asks for full access and then only reads. You can check this for yourself: the source code is available on request.

One exception, and it is worth being precise about

If you tell the app that an entry should always leave you available — or always take the day — it has to recognise that entry next time, and the only thing an entry reliably offers is its title.

The title is not what gets stored. What gets stored is a fingerprint of it: the title run through a one-way function, keyed by a random number held in your phone's Keychain. It matches the same entry every time and cannot be turned back into the title. Someone holding the file, even with a list of every matter you have ever been in, could not work out which is which without that key.

The Rules screen still shows you the real names. It gets them from the calendars already open in front of it, not from the file.

Marking a single day, or one occurrence of an entry, stores a date and an identifier from the calendar. A line you type over a month stores what you typed, because that is your words rather than your diary's.

What else is kept on your phone

The app remembers your settings: your name and letterhead, which calendars to read, your rules, and any day you have marked by hand. All of it is kept in a file on your phone, scrambled with a key held in the phone's Keychain. The key never leaves the device and is not included in backups, so it stays on the one phone it was made on.

Deleting the app deletes all of it. So does "Erase all data" in Settings.

Public holidays

If you add a public holiday calendar, the app hands the address to iOS and iOS subscribes to it, the same as if you had typed it into the Calendar app yourself. The app does not fetch it, and whoever publishes that calendar sees a request from your phone, not from us. We do not run those calendars and have nothing to do with them.

Paying

The free fortnight, and the one-off payment after it, are handled by Apple through the App Store. We never see your card, your address, or your name. Apple tells the app one thing: whether this Apple Account has paid.

Other apps

When you send your dates, iOS hands the document to whichever app you chose — Mail, Messages, or anything else. What happens to it after that is between you and that app.

Changes

If this page changes, the date below changes with it. There is nothing to opt in or out of, because there is nothing being collected.

Asking

Write to hello@fisheggs.au.