dabji Terms of Use

1. Definitions

1. App — the mobile app dabji that we distribute on the App Store and Google Play.
2. User — a person who installs and uses the App, including people under 14 (section 2).
3. Solver model — the AI model file that is downloaded to the device when the App is first run and that solves questions on the device.
4. Solving — one run in which a photo of a question taken by the user is passed to the solver model to produce the thinking, solution and answer.
5. Solve — a credit used for one solving run. Solves are stored only on the device.
6. Ads — the rewarded ads and banner ads that an ad network (Google AdMob) shows in the App.

2. Using the App without an account

1. The App has no sign-up or login. You can use it as soon as it is installed, and we receive no information that identifies you. Personal information is covered by the Privacy Policy.
2. Your solves and the solver model are stored only on the device. They are lost when you delete the App or change devices, and they cannot be moved to another device or restored.
3. Anyone, including elementary, middle and high school students, can use the App. We recommend that users under 14 use the App with guidance from a parent or guardian.

3. What the service does and its limits

1. The App takes one question from a photo you take with the camera or pick from your photos, solves it with the solver model on the device, and shows the thinking, the solution and the answer. Solving does not use the internet.
2. Results are generated by AI and can be wrong. We do not guarantee that results are accurate or complete. Use results only as a reference to help you learn, and check the solution yourself. When the App shows “Not sure” or “Couldn’t find an answer”, the result is especially unreliable.
3. The App is designed for elementary to high school questions in subjects such as math, science, social studies, language arts and English, written in Korean or English. Its solving was checked mainly with questions from the Korean curriculum. It may fail to solve, or solve incorrectly, other questions, questions written in other languages, blurry or cut-off photos, and photos that mix several questions.
4. The solver model must be downloaded over the internet once (about 3GB), and solving speed and quality depend on the device’s memory and performance. On devices below the recommended specs, solving may be slow or fail.
5. The App is not made to replace exams or assessments at schools or other educational institutions, or to break their rules (section 5).

4. Free use, ads and solves

1. The App is free. We earn revenue from ads in the App, and there are no paid purchases or subscriptions.
2. Solves go up and down under the rules below. The numbers may change with App updates, and we will tell you in the App if they do.
   • You get 3 solves when you first run the App.
   • You get 3 solves when you watch a rewarded ad to the end. If you close it early, you get nothing. You can hold up to 15 solves, and you can get more when you have 12 or fewer.
   • One solve is used the moment you tap “Solve”, “Solve again” or “Try again”.
   • If solving ends because of an App error (solving failed, not enough memory, or the model or photo could not be loaded), the solve you used is returned. It is not returned if you stop solving, leave the App, or the App is closed, or if the answer is uncertain or missing.
3. Solves have no cash value. They cannot be refunded, exchanged for cash, transferred, or moved to another device. When you have 0 solves you cannot solve, and watching a rewarded ad requires an internet connection.
4. The content of ads is decided by the ad network and advertisers. We send every ad request as child-directed, non-personalized and rated for general audiences, but we cannot review each ad in advance. Products and services promoted in ads, and any transactions with them, have nothing to do with us.
5. When ads cannot be loaded (no internet, or no ads available), you cannot get solves. We do not guarantee that ads are always available.

5. Your responsibilities

1. You are responsible for the photos you take and how you use them. Photograph textbooks, exam papers and other works of others only within private use such as personal study, and do not copy or distribute the results as they are.
2. If using the App in an exam, assessment or assignment breaks the rules of your school or educational institution, do not use it. You are responsible for the consequences of breaking those rules.
3. You check and judge the results yourself. Decisions about learning, exams, admissions and the like that rely on the results are yours.
4. You follow applicable laws, these terms and the rules of the app store.

6. Prohibited conduct

You must not:

• Create invalid traffic that breaks the ad network’s policies, for example by using a program that watches or taps ads automatically
• Modify or reverse engineer the App, or tamper with data on the device such as your solves
• Extract, redistribute or sell the solver model files the App downloads in a way that breaks each model’s license (section 7)
• Use the App to infringe the rights of others or for unlawful purposes
• Impersonate us or our partners

7. Intellectual property and third-party software

1. We hold the rights to the App’s software, design, text and logo. We grant you a non-transferable license to use the App for personal, non-commercial purposes.
2. You are free to use the photos you take and the results the App produces. We do not receive or store your photos and results, and we claim no rights to them.
3. The App includes or downloads the following third-party software and models, each under its own license. The full list and license texts are under “Open source licenses” on the App info screen.

   Name	Use	License
   Qwen3.5-4B (Alibaba Cloud, MLX 4-bit conversion: mlx-community)	Solver model (iPhone with 7GB of memory or more)	Apache License 2.0
   Gemma 4 E4B · E2B (Google, LiteRT-LM conversion: litert-community)	Solver model (Android, and iPhone with less than 7GB of memory)	Apache License 2.0
   MLX Swift · MLX Swift LM (Apple)	Inference runtime	MIT License
   LiteRT-LM (Google)	Inference runtime	Apache License 2.0
   Google Mobile Ads SDK (Google)	Ads	Google’s terms of service
   Pretendard (Kil Hyung-jin)	Font	SIL Open Font License 1.1

8. Changes to and discontinuation of the service

1. We may replace the solver model, change features or the rules for solves, or adjust the supported devices and operating system versions. We will announce important changes in App update notes or on this page.
2. The solver model file is downloaded from servers run by a third party (Hugging Face). Downloads may be temporarily unavailable because of that third party, and you can keep solving with a model you have already downloaded.
3. We may stop distributing the App for business or technical reasons. If we do, we will announce it on this page at least 30 days in advance. Installed copies of the App and the solves on your device will keep working, but getting more solves through ads may no longer be possible.

9. Limitation of liability

1. The App is provided free of charge and “as is”. To the extent permitted by law, we do not guarantee that results are accurate, that the App will run without interruption, or that it is fit for any particular purpose.
2. We are not liable for disadvantages in learning, exams or assessments caused by wrong results, for device heat, battery drain or lack of storage, for data charges for downloading the solver model, or for transactions promoted by ads. This does not apply to damage caused by our intentional misconduct or gross negligence.
3. This section does not limit any rights you have under mandatory consumer protection laws.

10. Ending use

1. You can stop using the App at any time by deleting it. Deleting it also removes the solver model and your solves from the device, and they cannot be restored.
2. If you break section 6, we may restrict that use. Because there are no accounts, restrictions may be applied through App updates or through the ad network’s policies.

11. Governing law and disputes

1. These terms and your use of the App are governed by the laws of the Republic of Korea.
2. Disputes arising from use of the App will first be settled by discussion through the contact details in section 14. If that fails, either party may bring a claim before the court with jurisdiction under the Korean Civil Procedure Act.

12. Changes to these terms

1. We may change these terms when laws or the service change. We will announce the changes and the effective date on this page at least 7 days before they take effect (30 days for changes that are unfavorable to you or significant).
2. If you keep using the App after the effective date, you are deemed to agree to the changed terms. If you do not agree, you can stop using the App and delete it.

13. If you downloaded the App from the App Store

If you downloaded the App from the Apple App Store, the following also applies.

1. These terms are between you and us, not Apple. We, not Apple, are responsible for the App and its content.
2. You may use the App only on Apple devices that you own or control, as permitted by the Usage Rules in the Apple Media Services Terms and Conditions.
3. We are responsible for maintenance and support of the App. Apple has no obligation to provide any maintenance or support.
4. Because the App is free, there is no purchase price for Apple to refund. To the maximum extent permitted by law, Apple has no other warranty obligation with respect to the App.
5. We, not Apple, are responsible for handling any claims that the App infringes a third party’s intellectual property, product liability claims, claims that the App fails to meet legal or regulatory requirements, and claims under consumer protection laws.
6. You confirm that you are not located in a country subject to a U.S. Government embargo, and that you are not listed on any U.S. Government list of prohibited or restricted parties.
7. Apple and its subsidiaries are third-party beneficiaries of these terms, and once you accept them, Apple will have the right to enforce these terms against you as a third-party beneficiary.

14. Contact

Send questions about these terms or using the App to: