1. Who we are and what this covers
Chartle is a mobile application published by Buffalo Dijital Hizmetler A.Ş. ("Buffalo", "we", "us"), a company incorporated in Türkiye. This policy explains what we collect when you use Chartle, why we collect it, who we share it with, and what you can ask us to do about it.
It applies to the Chartle mobile application and to chartleapp.com. It does not apply to the App Store, Google Play, or any other service you reach from Chartle, each of which has its own policy.
For the purposes of the Turkish Personal Data Protection Law No. 6698 ("KVKK") we act as the data controller. Where the EU General Data Protection Regulation ("GDPR") applies to you, we act as controller within the meaning of that regulation.
Contact: chartle@buffalostudio.co
Address: Cevizli Mah. Zuhal Cad. A Blok No: 46/50, 34846 Maltepe / İstanbul, Türkiye
2. What Chartle does not ask for
It is easier to describe Chartle by what it leaves out.
Chartle has no accounts. There is no sign-up, no password, no email address, and no social login. We do not ask for your phone number, your date of birth, or any financial account.
Chartle does not access your camera, photo library, microphone, contacts, calendar, health data, or precise location. It holds no brokerage connection and cannot see any portfolio, trade or balance, because it never asks for one. The charts inside the app are historical market data we ship with it, not anything of yours.
There is no chat, no profile, no comment section and no way for one user to see another. Nothing you do in Chartle is visible to another person.
3. What we collect
3.1 What you tell us
When you first open Chartle it asks six short questions so the app can shape a learning plan: a first name or nickname, how much experience you have with charts, which topics you want to cover, what you are aiming for, how often you want to practise, and how confident you feel. That is the entire set. The name is used to address you inside the app; you may enter anything you like, and it is never shown to anyone else.
3.2 What the app records as you use it
To show your progress and to decide which question to ask you next, Chartle records how you play: which patterns you have been shown, which you answered correctly, your day streak, your experience points, and a bounded history of your recent sessions. This is stored on your device, and is associated with the anonymous identifier described below.
3.3 Identifiers
Chartle creates an anonymous identifier for your installation. It is a random value. It is not your name, your email or your device's serial number, and it is not linked to any identity we hold, because we hold none.
On iOS, if — and only if — you allow tracking when the system asks, we may receive Apple's Advertising Identifier (IDFA). On Android the equivalent is the Google Advertising ID. These are used for advertising attribution as described in section 5. If you decline, Chartle works exactly as it did before; the only difference is that we cannot tell which advertisement, if any, brought you to the app.
3.4 Usage and diagnostics
We collect which screens you open, which features you use, and events such as starting a session, answering a question, or opening the subscription screen. We also collect technical data that arrives automatically with any app: device model, operating system version, language, country, and app version.
If Chartle crashes, we receive a crash report containing the technical state of the app at that moment. It contains no answers, no name and no message.
3.5 Purchases
If you buy a subscription, the purchase is made through Apple or Google, not through us. We never see or receive your card number, billing address or bank details. What we receive is the fact that a subscription exists, its product identifier, its status, and the store's anonymous transaction identifiers, so the app knows to unlock the paid features on your device.
3.6 Notifications
If a free trial is available to you and you accept the system prompt, Chartle schedules one local reminder before the trial ends. It is generated on your device by the app itself. No server is involved and no message is sent to us.
4. Why we process it, and on what basis
| Purpose | What it uses | Legal basis (KVKK / GDPR) |
|---|---|---|
| Running the app and keeping your progress | Onboarding answers, progress, anonymous identifier | Performance of a contract |
| Personalising the learning plan and the questions asked | Onboarding answers, progress | Performance of a contract |
| Managing subscriptions and unlocking paid features | Purchase status, product identifiers | Performance of a contract |
| Keeping the app working, fixing crashes, preventing abuse | Diagnostics, technical data | Legitimate interest |
| Understanding which features are used and improving them | Usage events, technical data | Legitimate interest |
| Measuring which advertisement brought a user to Chartle | Advertising identifier | Explicit consent (the system prompt) |
| Meeting our legal and accounting obligations | Subscription records | Legal obligation |
Where we rely on consent, you may withdraw it at any time — for tracking, in your device's privacy settings; for notifications, in your device's notification settings. Withdrawal does not affect processing carried out before it.
5. Who we share it with
We do not sell personal data, and we do not share it for anyone else's advertising.
We use a small number of service providers who process data on our instructions:
- Google (Firebase Authentication, Cloud Firestore, Analytics, Crashlytics, Remote Config) — the anonymous identifier, onboarding answers, usage events and crash reports.
- Mixpanel — usage events and screen views, under the anonymous identifier.
- AppsFlyer — install attribution, and the advertising identifier where you have allowed it.
- RevenueCat — subscription status, so the app knows what you have access to.
- Apple and Google, as the stores that process the payment itself.
We may also disclose data where a law, a court, or a competent authority requires it, and where it is necessary to establish, exercise or defend a legal claim.
6. Transfers abroad
The providers above operate servers outside Türkiye, including in the United States and the European Union. Your data is therefore transferred abroad within the meaning of Article 9 of the KVKK, and, where the GDPR applies, outside the EEA.
We rely on the safeguards those providers offer for such transfers, including standard contractual clauses approved by the European Commission where applicable. You may request a copy of the relevant safeguard using the contact address in section 1.
7. How long we keep it
Progress and answers stay on your device until you delete the app. Deleting the app removes them from the device.
Data held by our providers under the anonymous identifier is kept while your installation is active and for a reasonable period afterwards, after which it is deleted or aggregated so that it can no longer be linked to an installation.
Records connected to a purchase are kept for as long as tax and commercial legislation requires us to keep them, which is currently ten years under Turkish law.
8. Age limitation
Chartle is intended for users aged 16 and over, and it is not directed at children. Its subject matter — reading financial charts — is not suitable for younger users.
We do not knowingly collect data from anyone under 16. If you believe someone under 16 has used Chartle, write to chartle@buffalostudio.co and we will delete what we hold.
9. Your rights
Under Article 11 of the KVKK, and under the GDPR where it applies to you, you may ask us to tell you whether we process your data and to give you a copy of it; to correct it if it is wrong or incomplete; to delete it; to restrict or object to how we use it; to transmit it to another controller where that is technically possible; and to tell you who we have shared it with. You may also object to a decision produced solely by automated analysis, and claim compensation for damage caused by unlawful processing.
Chartle makes no decision that produces a legal effect for you. The app adapts which questions it asks and which patterns it shows; nothing more.
Send requests to chartle@buffalostudio.co. We answer within thirty days at the latest, and free of charge unless the request is manifestly excessive or repetitive. Because we hold no identity information, please write from the address you wish us to reply to and tell us as much as you can about your installation; without something to match, we may be unable to locate any data that relates to you.
You also have the right to complain to the Turkish Personal Data Protection Authority (KVKK), or, in the EEA, to your local supervisory authority.
10. Security
Data in transit is encrypted. Data held on your device is stored in the application's own storage area, which the operating system isolates from other apps. Access to the tools listed in section 5 is restricted to the people who need it.
No system is perfectly secure, and we do not claim otherwise. What we can say is that the amount of personal data Chartle holds is deliberately small: there is no account to compromise and no payment detail to lose.
11. Marketing
Chartle does not currently collect email addresses and we do not send marketing email. If that changes, we will ask for your address and your consent separately, explain what we intend to send, and give you a way to unsubscribe in every message. We will not repurpose data collected under this policy for marketing without telling you first.
12. Changes to this policy
If we change how Chartle handles personal data, we will update this page and change the date at the top. If the change is significant, we will say so in the app before it takes effect.
13. Contact
Buffalo Dijital Hizmetler A.Ş.
Cevizli Mah. Zuhal Cad. A Blok No: 46/50, 34846 Maltepe / İstanbul, Türkiye
chartle@buffalostudio.co
chartleapp.com