Lingo Diary Terms of Service

Last Updated: May 6, 2026

Welcome to Lingo Diary (the "Service" or the "App"). This Service is provided by SPARKLECT CO., LTD. ("we", "us", or "our").

Please read these Terms carefully before using the Service. By registering an account, you acknowledge that you have read, understood, and agreed to all terms below.

1. Nature and Scope of the Service

The Service uses artificial intelligence (LLM) technology to guide users through conversations in their target language for diary writing and language learning purposes.

  • AI-generated content: Grammar corrections, expression suggestions, diary content, voice transcription, and pronunciation teaching provided by the Service are automatically generated by AI models and are for reference only. They do not constitute professional language teaching advice.
  • Feature differences: The Service offers multiple membership tiers, each with different feature access rights and points quotas (see Section 3).

2. AI Disclaimer (Important)

Because the core functionality is AI-generated, we do not guarantee the absolute accuracy, completeness, or safety of generated content. By using the Service, you agree to assume the following risks:

  • Grammar correction accuracy: AI-provided grammar corrections, expression suggestions, and translations are algorithmically generated references that may contain errors. They should not be used as the sole basis for academic examinations or professional translations.
  • Voice transcription and pronunciation teaching: Voice message transcripts, pronunciation annotations, and pronunciation teaching content are also AI-generated and may contain misjudgments or errors. They are provided for learning reference only and must not be used as the basis for language proficiency tests or professional assessments.
  • Diary content accuracy: AI-generated diary content may not fully and accurately reflect your original intent. Users should verify the appropriateness of the content themselves.

3. Membership Plans and Benefits

The Service offers multiple membership tiers. The names, specific benefits, feature limits, points quotas, and usage deduction rules of each plan are governed by the plan description page currently published in the App. We reserve the right to adjust plan content and values at any time.

3.1 Points System

The Service operates on a dual-track points system of "permanent points + monthly points", which are deducted to use features such as chat, voice messages, and text-to-speech (TTS):

  • Monthly points: Granted by your subscription plan and reset at the start of each billing cycle. They will be adjusted or set to zero when a subscription ends, is downgraded, or is refunded.
  • Permanent points: Earned through the following methods and never expire:
    • A first-time signup gift when you create your account.
    • Watching rewarded advertisements (each completed view grants the corresponding number of permanent points).
  • Deduction order: The system deducts monthly points first, and falls back to permanent points when monthly points are insufficient.

3.2 Nature and Limitations of Points

  • Non-redeemable, non-transferable: All points (including permanent points earned by watching advertisements) are an internal usage allowance within the Service only. They carry no monetary value, cannot be exchanged for cash, goods, or other services, and cannot be transferred to other users.
  • Reward amount adjustments: The number of points granted per rewarded-ad view is determined by us based on operational considerations, and we reserve the right to adjust it at any time.
  • Violations: If we reasonably determine that you have obtained points by improper means (for example, abusing the rewarded-ad SSV mechanism, manipulating accounts, or using emulators or automated scripts to generate fraudulent reward views), we have the right to immediately revoke the relevant points and may, depending on the severity, suspend or terminate your account.
  • Account deletion: Once your account is deleted, all points (including unused permanent and monthly points) are immediately extinguished and will not be reissued, refunded, or credited.

4. Subscription and Payment Policy

4.1 Subscription fees

  • Subscription pricing, billing cycles (e.g., monthly, annual), and promotional offers are subject to the information shown in the app store (App Store / Google Play) and the in-app purchase page.
  • Prices may vary due to exchange rate fluctuations, regional tax laws, or promotional campaigns.

4.2 Auto-renewal

Subscriptions renew automatically unless auto-renewal is turned off at least 24 hours before the end of the current subscription period. Charges will be deducted from your App Store or Google Play account within 24 hours before the end of the current billing cycle.

4.3 Cancellation

You may manage or cancel your subscription at any time through your app store account settings. After cancellation, benefits remain available until the end of the current billing period.

4.4 Refunds

All subscription transactions are processed by the app store platform (Apple / Google). The Service cannot process refunds directly. Please follow the relevant platform's refund policy.

4.5 Free Trial (Introductory Offer)

Some subscription plans offer first-time subscribers a limited-time free trial (such as a 7-day free trial). The trial terms are as follows:

  • Eligibility: Trial eligibility is determined by the app store (Apple / Google) according to its account-level rules. Each Apple ID / Google account is typically eligible for one trial only.
  • Scope of benefits: During the trial, you may access the full features and monthly points quota of the corresponding plan.
  • Automatic conversion to paid subscription: At the end of the trial, the subscription will automatically convert to a paid subscription and you will be charged according to the plan's billing cycle, unless you turn off auto-renewal via App Store / Google Play at least 24 hours before the trial ends.
  • Cancel anytime: You may cancel the subscription at any time during the trial. After cancellation, you may continue to use the benefits until the end of the trial period and will not be charged at expiration.

5. Fair Use Policy

To protect service quality for all users and prevent malicious abuse of system resources, in addition to the "points-deduction rules" described above (see Section 3.1), the Service reserves the right to operate dynamic risk-control and rate-limiting mechanisms:

  • Dynamic limits: The Service may impose dynamic caps on short-term API call frequency, computational resource consumption, or abnormal usage patterns. These limits apply to all users (including both free and paid members) and are independent of your points balance — abnormal behavior may trigger limits even when you still have sufficient points.
  • Consequences when triggered: When the system detects abnormal usage patterns, it may temporarily restrict your usage privileges, reduce response speed, or ask you to try again later.
  • Rule adjustments: Limit quotas, calculation periods, and reset times may be adjusted dynamically based on system load without individual prior notice.

You agree that these limits are necessary measures to maintain service stability and do not constitute a breach of contract or infringement of your rights.

6. Intellectual Property

6.1 App rights

The Service interface design, source code, database structure, and trademarks are owned by us.

6.2 User content rights

  • All content you create through the Service (including conversation messages and AI-generated diary entries) remains your intellectual property.
  • To provide the Service, you grant us the necessary rights to process, store, and transmit your content during the operation of the Service.

7. Service Changes and Termination

We reserve the right to modify, suspend, or terminate any part or all functionality of the Service at any time. Significant changes will be announced within the App.

8. Contact Us

If you have any questions about these Terms of Service or our data handling practices, please contact us through the following:

  • Company name: SPARKLECT CO., LTD.
  • Email: service@sparklect.com