Zimo – Terms of Service

Last updated: 6 September 2026

1. Introduction and Acceptance

These Terms of Service ("Terms") govern your access to and use of the Zimo mobile application, including all related content, features, and services (collectively, the "App"). The App is a Chinese language learning application offered by:

Lumen Haendler, trading as Lumen Haendler Software Engineering
Sole proprietorship (Einzelunternehmen)
Kirchstraße 20, 88699 Frickingen, Germany
Email: contact@zimo-characters.com

("Zimo", "we", "us", or "our").

By downloading, installing, registering for, or using the App, you agree to be bound by these Terms. If you do not agree to these Terms, do not use the App.

2. Eligibility and Minors

You must be at least 16 years old to create an account and use the App. By registering, you confirm that you meet this requirement.

If you are 16 or 17 years old, you are a minor under German law. In that case you may only enter into a paid subscription or make any other purchase with the consent of your parent or legal guardian. By making a purchase, you confirm that such consent has been obtained. We reserve the right to request proof of consent and to suspend or terminate accounts where such consent is missing.

The age limit reflects Art. 8 GDPR, under which the processing of a child's personal data in Germany requires parental consent below the age of 16. Details on data processing are set out in our Privacy Policy.

3. Description of the Service

Zimo is a spaced-repetition-based learning application for Mandarin Chinese, covering characters, vocabulary, and grammar approximately aligned with HSK levels 1–5. The App is available for iOS and Android.

The App offers:

• a free tier, which includes at least the first level of learning content; the number of levels available to you free of charge is shown in the App; and
• paid subscription plans and a one-time purchase ("Premium"), which unlock the full learning content and additional features.

The scope of the free tier may differ between users and may change over time, for example while we test different introductory offers. The scope that applies to you is always the one displayed in the App.

We continuously develop the App. The specific scope of content and features, including the boundary between free and paid content, may change over time. Section 12 (Changes to the Service) applies.

4. Beta Features

Parts of the App may be offered as beta or test versions (for example via Apple TestFlight or Google Play Open Testing) or labeled as "beta" within the App. Beta features are provided for testing purposes, may contain errors, may be modified or discontinued at any time, and may not perform reliably. Learning progress or data associated with beta features may be reset or lost. To the extent permitted by law, beta features are provided "as is."

5. Account Registration

To use the App, you must create a user account. You agree to:

• provide accurate and complete registration information and keep it up to date;
• keep your login credentials confidential and not share your account with third parties;
• notify us promptly if you suspect unauthorized use of your account.

You are responsible for all activity occurring under your account, unless such activity results from circumstances beyond your control. Each person may maintain only one account. We may refuse registration or suspend accounts for good cause.

6. License and Intellectual Property

Subject to your compliance with these Terms, we grant you a limited, non-exclusive, non-transferable, non-sublicensable, revocable license to install and use the App on devices you own or control, solely for your personal, non-commercial language learning.

All content in the App — including learning content, character and vocabulary databases, mnemonics, audio recordings, software, design, graphics, and trademarks — is owned by us or our licensors and protected by copyright and other intellectual property laws. You may not:

• copy, reproduce, distribute, publicly display, or create derivative works of the App or its content, except as expressly permitted;
• extract, scrape, or systematically download learning content (including via automated tools, bots, or scripts);
• reverse engineer, decompile, or disassemble the App, except where such restriction is prohibited by mandatory law;
• remove or alter any proprietary notices;
• use the App or its content to develop or train competing products or machine learning models.

7. Purchases, Billing, and Free Tier

7.1 Purchases via App Stores

All paid plans are purchased exclusively through the Apple App Store or Google Play. The purchase contract for the payment processing is concluded via the respective platform, and billing, payment methods, taxes, and receipts are handled by Apple or Google in accordance with their terms. We do not process or store your payment card details.

7.2 Subscription Terms and Auto-Renewal

Subscriptions are offered for the periods and at the prices displayed in the App and the relevant app store at the time of purchase. Unless cancelled, subscriptions renew automatically at the end of each billing period at the then-current price for your plan. You can cancel auto-renewal at any time in your Apple App Store or Google Play account settings; cancellation takes effect at the end of the current billing period. Deleting the App does not cancel your subscription.

7.3 One-Time Purchase ("Lifetime")

We may offer Premium as a one-time purchase instead of a subscription. A one-time purchase is not a subscription: it does not renew, there is no billing period, and there is nothing to cancel. It grants access to Premium for as long as we operate the App, subject to Section 12 (Changes to the Service) and Section 13 (Term and Termination).

A one-time purchase does not entitle you to features or content that we offer separately from Premium in the future, unless stated otherwise at the time of the offer.

7.4 Price Changes

We may change prices for future billing periods. Price changes will be communicated in advance in accordance with the applicable app store rules; where required, they take effect only upon your consent or after you have had the opportunity to cancel before the change applies. A one-time purchase already made is not affected by later price changes.

Promotional or early-adopter pricing may be limited in time or scope as described at the time of the offer. Where an early-adopter price is described as locked, it remains valid for as long as your subscription runs without interruption; if you cancel and subscribe again later, the price then current applies.

7.5 Free Trials and Promotions

Where free trials or promotional offers are available, their conditions (duration, eligibility, conversion into a paid subscription) are displayed before activation. Unless cancelled before the end of the trial, the trial converts into a paid subscription at the displayed price. Each user is eligible for a free trial only once, unless expressly stated otherwise.

7.6 Refunds and Right of Withdrawal

Refund requests for purchases made via the Apple App Store or Google Play must be directed to Apple or Google and are governed by their respective refund policies.

If you are a consumer in the European Union, you have a statutory 14-day right of withdrawal. How it applies depends on what you bought:

• Subscriptions are digital services. If you ask us to begin performance during the withdrawal period and acknowledge this, and you then withdraw, you owe a pro-rated amount for the period already elapsed.
• One-time purchases (Lifetime) are digital content. If you give your express consent to immediate performance and acknowledge that you thereby lose your right of withdrawal, that right lapses once performance begins.

In both cases the consent is obtained by the app store as part of the purchase flow. Your statutory rights remain unaffected.

8. Referral Program and Promotional Codes

We may offer a referral program under which users can invite others and receive benefits (such as free Premium time or discounts). The specific conditions are described in the App. The following always applies:

• referral rewards have no cash value and cannot be transferred, sold, or exchanged for money;
• self-referrals, fake accounts, mass or automated distribution (spam), and misleading promotion are prohibited;
• we may modify, suspend, or discontinue the referral program at any time with effect for the future; benefits already validly earned remain unaffected;
• we may revoke rewards obtained through abuse or violation of these Terms.

9. Acceptable Use

You agree not to:

• use the App for any unlawful purpose or in violation of these Terms;
• interfere with or disrupt the operation of the App, its servers, or networks;
• attempt to gain unauthorized access to the App, other users' accounts, or our systems;
• circumvent technical restrictions, paywalls, or usage limits;
• use automated means (bots, scrapers, crawlers) to access the App;
• resell, rent, or commercially exploit the App or access to it;
• upload or transmit malware or harmful code.

We may suspend or terminate access in the event of violations. Section 13 (Termination) applies.

10. Learning Data and User Progress

Your learning progress (e.g., reviewed items, SRS stages, statistics) is stored on our servers to provide the service across devices. While we take reasonable measures to protect this data, we recommend that you do not rely on the App as the sole record of information important to you. In the event of account deletion or termination, learning progress may be irretrievably deleted.

Information on the processing of personal data is provided in our Privacy Policy, available at https://zimo-characters.com/privacy.

11. Third-Party Services

The App relies on third-party services, including Apple (App Store, TestFlight), Google (Google Play), and hosting, backend, subscription-management and notification-delivery providers. Your use of the App may also be subject to the terms of these third parties (e.g., Apple Media Services Terms, Google Play Terms of Service). We are not responsible for third-party services beyond our statutory liability. The providers we use and the data they process are listed in our Privacy Policy.

Apple-specific terms (iOS users): These Terms are concluded between you and us, not with Apple. Apple has no obligation to provide maintenance or support for the App and is not responsible for addressing any claims relating to the App (including product liability, legal compliance, or intellectual property claims). Apple and its subsidiaries are third-party beneficiaries of these Terms and may enforce them against you.

12. Changes to the Service and to these Terms

We may modify, expand, or discontinue features of the App, in particular to develop the service further, adapt to technical or legal requirements, or for security reasons. If a change materially reduces the core features of a paid plan, you will be informed and may cancel your subscription; if you hold a one-time purchase, you may in that case claim the statutory remedies for digital content.

We may amend these Terms with effect for the future for good cause (e.g., changes in law, new features, changes to our business model). We will notify you of amendments in the App or by email at least 30 days before they take effect. If you do not object within this period or continue to use the App after the effective date, the amended Terms apply, provided we have specifically informed you of the consequences of not objecting. Your right to cancel at any time remains unaffected. Amendments that would materially disadvantage you and alter the contractual balance require your express consent.

13. Term and Termination

You may stop using the App and delete your account at any time in the App settings or by contacting us. Deleting your account does not automatically cancel an active subscription — cancel it separately via the App Store or Google Play.

We may suspend or terminate your account for good cause, in particular in the event of serious or repeated violations of these Terms, fraud, or abuse. Where reasonable, we will issue a warning first. In the event of a justified termination for cause, there is no entitlement to a refund of prepaid fees, except where mandatory law provides otherwise.

14. Warranty

For consumers in the European Union, the statutory warranty rights for digital content and digital services (in Germany: §§ 327 et seq. BGB) apply. Beta features are subject to Section 4.

15. Limitation of Liability

We are liable without limitation for damages caused intentionally or by gross negligence, for injury to life, body, or health, under the German Product Liability Act (Produkthaftungsgesetz), and where we have assumed a guarantee.

In the event of slight negligence, we are liable only for the breach of essential contractual obligations (obligations whose fulfillment is a prerequisite for the proper performance of the contract and on whose compliance you may regularly rely — Kardinalpflichten), and in such cases only up to the amount of the typical, foreseeable damage.

Any further liability is excluded. The above limitations also apply in favor of our legal representatives and agents.

The App is a learning aid. We do not warrant any particular learning outcome, exam result (e.g., HSK certification), or level of language proficiency.

16. Indemnification

To the extent permitted by law, you agree to indemnify us against claims by third parties arising from your culpable violation of these Terms or applicable law in connection with your use of the App, including reasonable costs of legal defense. This does not apply where you are not responsible for the violation.

17. Governing Law and Jurisdiction

These Terms are governed by the laws of the Federal Republic of Germany, excluding the UN Convention on Contracts for the International Sale of Goods (CISG). If you are a consumer, this choice of law does not deprive you of the protection of mandatory provisions of the law of your country of habitual residence.

If you are a merchant, a legal entity under public law, or a special fund under public law, the exclusive place of jurisdiction is Frickingen, Germany.

Consumer dispute resolution: We are neither obliged nor willing to participate in dispute resolution proceedings before a consumer arbitration board (§ 36 VSBG).

18. Miscellaneous

• Severability: If any provision of these Terms is or becomes invalid, the validity of the remaining provisions remains unaffected.
• Assignment: We may transfer our rights and obligations under these Terms to a legal successor (e.g., in the context of a corporate restructuring); you will be informed of any such transfer and may terminate the contract if the transfer is unreasonable for you.
• No waiver: Our failure to enforce any provision does not constitute a waiver of that provision.
• Entire agreement: These Terms, together with the Privacy Policy and any conditions displayed in the App at the time of purchase, constitute the entire agreement regarding the use of the App.

19. Contact

For questions about these Terms, please contact us at:

Lumen Haendler, trading as Lumen Haendler Software Engineering
Kirchstraße 20, 88699 Frickingen, Germany
Email: contact@zimo-characters.com