Last updated: October 23, 2026
This Privacy Policy applies to all games and apps developed and published by Serhat Kızılkaya (also known as Fourty Poles Studio), including: Pyramidka: Ring Stack Puzzle, 2000 IQ! - Tricky Puzzles, Nut Out! - Screw Puzzle, Stickman: Going Home, Color Laser Pop, 2001 IQ - Tricky Brain Puzzles, DUEVO and Katre – Dhikr Drops. Sections marked ★ DUEVO apply only to the DUEVO app, and sections marked ★ KATRE apply only to the Katre app.
Our games may collect the following data automatically through third-party services:
We do not collect names, email addresses, passwords, or any personally identifiable information directly through our games.
DUEVO collects the following information to provide its accounting and finance features:
Account & Identity
User-Entered Data
Automatically Collected
We do not sell your personal data to third parties. We do not use your financial data for advertising purposes.
Katre is a dhikr counter. It works fully offline and shows no ads. It does not use the Advertising ID and contains no advertising trackers; it only keeps anonymous usage counts (see “Automatically Collected”).
Kept only on your device
This data never leaves your phone unless you join the optional rankings or keep your profile with Google. Uninstalling the app or clearing its data deletes it from the phone.
Backup with your Google account (only if you connect Google)
Optional rankings (only if you choose to join)
Account & Identity
Automatically Collected
Device permissions
If you join the rankings, other Katre users can see your nickname, profile picture, chosen place, level, dhikr totals and counts in the rankings, streak, the month you joined, and a Premium badge if you have Premium. Users can report an unsuitable nickname or photo; a report records only how many times a profile was reported and when, not who reported it.
Totals for countries, provinces and districts are shown as combined sums and are not linked to any person.
We do not sell your data, do not use it for advertising, and do not share it with anyone except the service providers listed below that run the app.
Where it is stored. Ranking data is stored in Google Firebase (Cloud Firestore and Cloud Functions) in Belgium (europe-west1). Profile photos are stored in Firebase Cloud Storage in the United States (us-east1). Crash reports are processed by Google. Data is encrypted in transit and at rest. By joining the rankings you consent to this transfer and processing outside Türkiye under Google’s safeguards.
How long. Your ranking profile is kept while you take part in the rankings, and your Google backup while your account exists. Crash reports are kept for up to 90 days by Firebase Crashlytics. Anonymous usage counts are kept for up to 14 months in Google Analytics.
Deleting your data. In the app go to Profile → Your community profile → Leave the rankings and delete my data. This immediately and permanently deletes your profile, nickname, photo, all your ranking entries, your Google backup and your account from our servers. Combined totals of countries, provinces and districts are not linked to you and remain. You can also request deletion by email at fourtypolesstudio@gmail.com; we process requests within 30 days.
Step-by-step: Delete your Katre account
KVKK (Türkiye). For users in Türkiye this section also serves as the clarification text (aydınlatma metni) under Law No. 6698 (KVKK). The data controller (veri sorumlusu) is Serhat Kızılkaya. Ranking data is processed on the basis of your explicit choice to join; crash data and anonymous usage counts on the basis of our legitimate interest in a working app. You may exercise your rights under Article 11 of the KVKK by contacting fourtypolesstudio@gmail.com.
Some of our games and DUEVO offer optional in-app purchases or subscriptions. All transactions are processed securely through the Apple App Store or Google Play. We do not store payment card information on our own servers.
For issues with purchases, contact us at fourtypolesstudio@gmail.com or reach out to Apple / Google support directly.
DUEVO may offer optional biometric authentication (fingerprint / Face ID) as a security feature. Biometric verification happens entirely on your device. We never collect, store, or transmit your fingerprint or face data. The app only receives a "verified / not verified" result from your device's operating system and never has access to the biometric data itself.
Some of our games display ads via Google AdMob, and some use the Meta (Facebook) SDK to measure our own ad campaigns on Instagram and Facebook. You can opt out of personalized advertising:
On iOS, Color Laser Pop will ask for permission before tracking, in accordance with Apple's App Tracking Transparency framework. If you decline, you will still see ads, but they will not be personalized based on tracking.
DUEVO does not display any advertisements.
Katre does not display any advertisements and does not use the Advertising ID.
Analytics and crash data collected through Firebase is retained per Google's standard retention policies. For DUEVO, your account data stored in Supabase is retained as long as your account is active. Upon account deletion, your data is permanently removed within 30 days.
In accordance with GDPR and applicable privacy laws, you have the right to:
To request account deletion or a data export, contact us at fourtypolesstudio@gmail.com. We will process your request within 30 days.
To protect against data loss and ensure service continuity, we create encrypted backups of the database. Backups are stored securely, access-restricted, and kept only as long as necessary.
Your data is stored on secure cloud servers operated by Supabase (hosted on Amazon Web Services), which may be located outside your country, including outside Türkiye and the European Union. By using the app, you consent to the transfer and processing of your data in these locations under appropriate safeguards.
For users in Türkiye, this policy also serves as the clarification text (aydınlatma metni) under Law No. 6698 (KVKK). The data controller (veri sorumlusu) is Serhat Kızılkaya. You may exercise your rights under Article 11 of the KVKK by contacting fourtypolesstudio@gmail.com.
Our apps are not directed to children under the age of 13. We do not knowingly collect personal information from children. If you believe your child has provided us with personal data, please contact us and we will delete it promptly.
We may update this Privacy Policy from time to time. Changes will be reflected on this page with an updated date. Continued use of our apps after changes constitutes acceptance of the updated policy.
For any questions about this Privacy Policy or your data, please contact us:
fourtypolesstudio@gmail.com