Your ledger never leaves your phone. The records you keep in Deyn — who owes you, what they bought, what they paid — are stored only on your device. There is no server holding them, and nobody at Deyn can read them. The only exception is a backup you choose to make to your own Google Drive.
What stays on your phone
All of it, unless you back it up yourself:
- The people you keep debt for — names, phone numbers, notes
- Every debt, payment and correction
- Your business details, employees and their permissions
- Your PIN, stored as a one-way hash that cannot be turned back into your PIN
What we do collect
When you create a Deyn account, the app sends us the following, once:
| What | Why |
|---|---|
| Your name | To know who our users are and contact them if needed |
| Your phone number | Same, and to recognise an account across reinstalls |
| Whether you use Deyn for personal or business | To understand how Deyn is used |
| A random installation id | So one phone is not counted twice |
| App version and platform | To know which versions are in use |
That is the complete list. None of your debt records are included — not a customer's name, not an amount, not a payment. We use this only to count users and understand growth.
Advertising measurement
We advertise Deyn on Facebook and Instagram. So that we can tell which adverts bring people to the app, Deyn includes Meta's measurement kit, which reports two things to Meta: that the app was installed, and that somebody created an account.
Nothing from your ledger is involved. Meta is not told your name, your phone number, who owes you money, how much, or anything you have written down. It receives a count and an advertising identifier for the device, which is how it matches an install to an advert.
If you would rather not be counted, Android lets you switch this off for every app at once: Settings → Privacy → Ads → Delete advertising ID. Deyn works exactly the same afterwards.
Reading payment notifications
Deyn can mark a debt as paid on its own when the money arrives. To do that it needs to see the payment message your mobile money service sends you — EVC Plus, for example. This is off until you turn it on, and Android asks you to grant it by hand in Settings → Notifications → Notification access.
Deyn does not ask for permission to read your SMS. It reads the notification your messaging app has already shown on screen, and only while the permission above is granted. You can withdraw it at any time in the same Android settings screen, and Deyn keeps working — you simply enter payments yourself, as before.
What happens to a notification it sees:
- Messages that do not look like money arriving are ignored and not kept
- A payment message is read on your phone, to work out how much arrived and from which number
- If that number is not someone in your book, nothing happens and the message is discarded
- If it is, Deyn asks you first. Nothing is written to your ledger until you tap Haa
None of this leaves your phone. The message, the amount and the sender are read on the device and never sent to us or to anybody else. Payment messages are held only until the app has looked at them, and are then deleted. Turning the permission off deletes what is held.
What we do not do
- No selling of your information to anyone
- No sharing of your debt records with anyone, ever
- No reading of your ledger by us, or by anybody else
- No reading of your SMS — Deyn never requests that permission
- No sending of your payment messages off the phone
- No location, contacts, camera, photos or microphone access
Google Drive backup
Deyn can keep a copy of your ledger in your own Google Drive. This is entirely optional and off until you turn it on.
The backup goes into a hidden folder that belongs to the Deyn app. Deyn
requests only the drive.appdata permission, which reaches that
folder and nothing else. Deyn cannot see, list or open any of your
own documents, photos or files in Drive.
How Deyn handles Google user data
| What Deyn does | |
|---|---|
| Accesses |
One scope only: drive.appdata. It reaches a hidden,
app-private folder in your Drive and cannot reach anything else in
your account. Deyn requests no other Google data — not your email,
not your contacts, not your files.
|
| Uses | Solely to write and read one backup file containing your own Deyn ledger. Nothing else, and never for advertising, profiling or training any model. |
| Stores | Nothing on our servers. The backup file lives in your Drive; the access token lives on your phone. We keep no copy of either, and no Deyn server ever receives your Google data. |
| Shares | With nobody. Your Google data is not transferred, sold or disclosed to any third party, and no human at Deyn can read it. |
| Deletes | Disconnect in the app, or remove Deyn's access at myaccount.google.com/permissions. Uninstalling Deyn removes the hidden folder and the backup with it. |
Deyn's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
Employees
If you invite an employee to your shop, their name and phone number are stored on the phones of that business. Entries an employee records stay in the business history permanently, even after they leave — that is how a ledger stays trustworthy.
Keeping and deleting your information
You can delete your Deyn account at any time from Profile → Delete account. That erases everything on your phone: your ledger, your people, your business. It cannot be undone, and we cannot recover it for you.
To have the signup information listed above removed from our records, email us and we will delete it.
Full instructions, including what to do if you can no longer open the app, are on the account deletion page.
Children
Deyn is a tool for running a business or managing personal lending. It is not directed at children, and we do not knowingly collect information from anyone under 13.
Changes
If this policy changes, the date at the top of this page changes with it.