CardSync collects no data. No account, no tracking, no advertising,
no analytics. Nothing is sent to us. Your files only go where you send them. To connect
over SSH to an SFTP server, the app includes open-source libraries published by Apple
(SwiftNIO, swift-crypto): they collect nothing, and their licenses can be read in the
app.
What the app accesses
The folders you designate yourself, through the iOS file picker.
CardSync has access to nothing else on your device or your drives: access is granted
folder by folder, by you.
Your photo library, read-only, and only if you choose an album as a
source. Permission is requested at that moment, and the app works without it if you
decline: folder sources remain available.
What the app does with your files
It copies them from the folder or album you chose to the destination you chose: a
folder, or an S3 or SFTP server you added yourself. Nothing else. Your files never go
anywhere but your own storage and your own accounts.
Network use
CardSync contacts no server of ours: we have none. Traffic can happen in four cases,
always between your device and your own accounts:
if you pick an S3 server you added as the destination, the app
sends your files to it, directly, with the access keys you gave it. Over Wi-Fi only,
unless you allow cellular data for that server. If you turn on read-back, each file is
downloaded again to be compared with the original;
if you pick an SFTP server you added as the destination, the app
connects to it directly, over SSH, with the password or key you gave it, and sends your
files over that encrypted connection. On the first connection it shows you the
fingerprint of the server's key so you can check it; it remembers it, and refuses to
connect if it changes. It asks the server to compute the digest of the files it stored
or, if the server cannot do that, reads them back. Over Wi-Fi only, unless you allow
cellular data for that server;
if you ask to back up photos no longer stored on the device, iOS fetches
them from your iCloud photo library. This can be turned off in each sync's
settings;
if you pick a folder hosted by an online service — iCloud Drive, Dropbox, Google
Drive… — as source or destination, that service downloads or uploads
the files, through the system.
In all four cases the exchange is between your device and the account or server you
chose. Nothing passes through us, and we have access to nothing.
If your server is on your local network — a NAS, a computer — iOS asks you to let
CardSync access it. The app uses that only to reach that server.
What is stored on your device
The app keeps, on the device and only there:
the list of your syncs — the folders chosen and their settings;
a history of recent runs — number of files, volume, duration, errors;
the list of servers you added — for S3, the address, bucket name and access key
ID; for SFTP, the address, port, user name, folder and the fingerprint of the server's
key (something the server gives to anyone, not a secret);
what opens each server, in the device's keychain: the S3 secret
key, or the SFTP password, or the private
key the app created on the device for SFTP. It never leaves: only the public
half of a key is shown, so you can add it to your server. None of it is displayed
again, synced by iCloud, or carried over in a backup to another device.
The first two files are visible in the Files app, under On My iPhone ›
CardSync. Everything goes away with the app if you delete it, with one caveat: iOS
may keep keychain contents after an uninstall. To be sure it is erased, delete the server
in CardSync before uninstalling. If you reinstall the app, it erases at launch any secret
that no longer matches a server.
Children
CardSync is not directed at children and gathers no information that could identify
anyone, of any age.
Changes
Any change to this policy will be published on this page, with a new update date.