Privacy Policy

This policy explains what information Handback collects when you use the Handback app for iPhone and this website, why, who we share it with, how long we keep it, and the choices you have. In this policy, “Handback”, “we” and “us” mean Jazz, which provides the app and is responsible (the “controller”) for your personal data.

1. What we collect

No account, an install id

Handback has no sign-up. When you first open it, the app creates a random install id and keeps it in your iPhone’s Keychain, so it survives a reinstall. Our services know you by this id. The first eight characters are shown at the bottom of Settings, so you can quote them if you write to us.

What stays on your phone

Your files and everything in them stay on your iPhone: the photos, their order, the titles and places you give them, return dates and reminders. Reminders are scheduled on the phone itself. Dispute letters and PDF exports are made on the phone too, and go only where you send them. We don’t have a copy of any of this unless you share a file (see below).

What goes to our evidence service

To make a record you can later prove, the app sends a small amount of information to our evidence service at handback.jazzyazilim.com, which runs on Cloudflare:

• For each file: a random file id, its kind (car, home, stay or item), the title you give it, the place if you enter one, and when you created it.
• For each photo: its SHA-256 fingerprint (a 64-character code computed from the photo; it can’t be turned back into the photo), whether it is a pickup or return photo, which step of the guide it belongs to, your phone’s time, and whether it was taken in the Handback camera or added from your library.
• Location, only if you turn it on. Location is off by default. If you turn on “Add approximate location to photos” in Settings, the app asks for iOS location permission and sends each photo’s position rounded to about 100 m, with its accuracy. The exact position never leaves your phone.
• Apple App Attest. The app asks Apple to confirm it is the genuine Handback app on a real iPhone. We receive and store a key identifier and the attestation Apple produces, and each request carries a signature from that key. This tells us nothing about who you are.

The service adds its own time to each photo record and links it to the record before it, in an append-only chain. Our servers also see your IP address when the app connects, as any web server does; it is kept in short-lived logs and is not stored with your records.

When you share a file

Sharing is always your choice, one file at a time. When you tap Create link on a file:

• the photos in that file are uploaded to storage run for us by Cloudflare (Cloudflare R2), and our server checks each one against the fingerprint it recorded;
• you get a link, https://handback.jazzyazilim.com/v/<id>. Anyone who has the link can see the file’s title, kind and place, its photos, the time of each one, whether the device passed App Attest, and the approximate location if you had it on. They don’t need an account. Don’t put anything in a title that you wouldn’t want the other side to read.
• photos you add to a shared file later, such as the return photos, are uploaded too, so the link stays complete;
• you can withdraw the link from the file at any time (Withdraw link, under the link). The page then says the link was withdrawn, and the photo addresses stop working straight away. The uploaded copies stay in our storage until you ask us to delete them (see section 6).

A person who opens your link can drop a copy of a photo on the page to check it against the record. That check runs in their browser; the photo they drop is not uploaded.

Purchases

Payments are handled by Apple. We never receive your card or bank details. To know which files you have paid for, purchases are recorded by our own purchase server (AppRevenue, which also runs on Cloudflare): the product, price and currency, Apple’s transaction ids and dates, your remaining file credits, and your install id, which is also passed to Apple with each purchase so renewals and refunds reach the right install. It also records when a price screen was shown and where in the app, so we can tell which screens are useful.

Device and usage information

• App version, device model, iOS version and language.
• Usage events, such as “file created” or “price screen shown”, collected with Google Analytics for Firebase.
• Crash reports and diagnostic data, collected with Firebase Crashlytics.
• Settings we adjust remotely, such as when return reminders fire, fetched with Firebase Remote Config.
• Your device’s identifier for vendors (IDFV), your answer to the tracking question, and, only if you allow tracking, its advertising identifier (IDFA). These are stored with your purchase records so ad results can be matched.

Ad measurement

After setup, iOS asks whether Handback may track you. Only if you tap “Allow” does the app start the Meta (Facebook) SDK, which we use to measure how well our ads work. It then receives app events such as installs, the usage events above and purchases, with your device’s advertising identifier. If you choose “Ask App Not to Track”, the Meta SDK is never started and Meta receives nothing from the app. You can change your choice at any time in iOS Settings → Privacy & Security → Tracking; a change takes effect the next time you open Handback. We also use Apple’s SKAdNetwork, which reports ad results to advertisers without identifying you.

Messages to us

If you email us, we receive what you write, your email address and anything you attach.

2. How we use it

We do not sell your personal information. We do not look at your photos, use them for advertising, or use them to train AI models.

3. Who we share it with

We use these service providers to run Handback. They process data on our behalf and only for the purposes above:

Apple processes payments, App Attest and the tracking permission under its own privacy policy. People you send a link to can see that file, as described above. We may also disclose information if the law requires it, to protect someone’s safety, to enforce our Terms of Use, or as part of a sale or reorganisation of our business (in which case this policy would continue to apply).

4. Permissions on your iPhone

• Camera: to take the photos for your files. Required to take photos in Handback.
• Photos: only if you choose to add a photo from your library. Those photos are marked “not taken in Handback” on the record.
• Location (while using the app): only if you turn on approximate location in Settings.
• Notifications: for return and deposit reminders, which are scheduled on your phone.
• Tracking: only for ad measurement, as described above.

5. Security

Data is encrypted in transit between the app, our servers and our providers. Our evidence service only accepts writes signed by an App Attest key that Apple confirmed. Photo links on a shared page are signed and stop working when you withdraw the link. No system is perfectly secure, so please keep your iPhone locked.

6. How long we keep it, and deleting it

• On your phone: your files stay until you delete them. To remove everything, go to Settings → Delete all files from this phone. This removes every file, photo and reminder from the phone and can’t be undone.
• Evidence records are kept so that a link you share, now or later, can still be checked. A file deleted from your phone is not deleted from the evidence service by that button. Withdraw any shared links first if you want them gone.
• To delete your records from our servers, email info@jazzgames.net with the install id shown in Settings. Within 30 days we delete the photos you uploaded, withdraw every link, and remove each file’s title and place. The chain entries themselves (fingerprint, times, the rounded location if you had it on, and whether the photo was taken in the app) stay, because each entry is sealed into every entry after it and removing one would break the proof for everyone else. They are not shown anywhere once your links are withdrawn, and a fingerprint can’t be turned back into a photo.
• Purchase records are kept where accounting or other legal obligations require it.
• Analytics event data is kept for up to 14 months and crash reports for up to 90 days.
• Emails are kept for as long as needed to help you, and up to 2 years.

Deleting files or the app does not cancel the yearly plan. Cancel it with Apple (see Support).

7. Your choices and rights

In the app you can turn location off, withdraw any shared link, and delete all files from your phone. In iOS Settings you can turn off tracking, location, camera and notifications at any time.

Depending on where you live (for example under the GDPR in the EU, the UK GDPR, Türkiye’s KVKK, or US state privacy laws), you may have the right to access your data, correct it, delete it, receive a copy in a portable format, object to or restrict certain processing, and withdraw consent. To use any of these rights, email info@jazzgames.net with the install id from Settings, so we can find your records. We will reply within 30 days. You also have the right to complain to your local data protection authority.

8. Children

Handback is not directed at children under 13, and we don’t knowingly collect personal information from them. If you believe a child under 13 has used Handback, contact us and we will delete their records.

9. International transfers

Our service providers operate in the United States and other countries, so your information may be processed outside the country where you live. When we transfer personal data out of the EU, the UK or Türkiye, we rely on appropriate safeguards, such as the European Commission’s Standard Contractual Clauses, adequacy decisions or the EU-U.S. Data Privacy Framework where the provider participates.

10. Changes to this policy

If we change this policy, we will update the date at the top of this page. If a change is significant, we will also tell you in the app before it takes effect.

11. Contact