Terms of Service

By creating an account or using rikai (the “Service”) you agree to these Terms and to our Privacy Policy. If you do not agree, do not use the Service. You confirm you meet the age requirement in Section 12.

rikai is an AI-native spaced-repetition vocabulary study app. You create or upload vocabulary decks and study them; optional AI features generate example sentences, definitions, and multilingual meanings. We may change, add, or remove features, limits, or pricing, with notice for material changes.

You sign in via Google or email. You are responsible for activity under your account and for keeping your login secure. We never see your Google password. Notify us promptly of any unauthorized use.

This is a binding billing agreement. Read it carefully.

Tiers.

• Basic — free. Up to 200 words per deck.
• Pro — $9.99 USD per month. Up to 2,000 words per deck, multilingual mode, and AI features. Includes a 3-day free trial for eligible new users.
• Max — $29.99 USD per month. Up to 6,500 words per deck, cloud-primary storage, and all Pro features.

Prices are in US dollars and exclude taxes (sales tax / VAT may be added at checkout where required).

Free trial → automatic paid renewal (please read). When you start the Pro 3-day free trial, you must provide a payment method. Unless you cancel before the trial ends, your subscription will automatically convert to a paid Pro subscription and you will be charged $9.99 per month.

Auto-renewal. All paid subscriptions (Pro and Max) automatically renew at the end of each billing period at the then-current price, and your payment method will be charged until you cancel. By subscribing, you give express, informed consent to these recurring charges.

How to cancel. You can cancel at any time, with no fee, from Settings → Billing in the app (self-serve, online, no phone call or email required). Cancellation takes effect at the end of the current paid period; you keep access until then. Cancelling during the free trial stops any charge.

Reminders and receipts. We will send you an email before your free trial ends and your first charge occurs, and a receipt after each charge. The billing descriptor on your statement will read approximately “RIKAI.AI”.

EU / UK consumers — right of withdrawal. If you are a consumer in the EU/UK, you normally have a 14-day right to withdraw from a purchase of digital services. By starting your subscription or trial, you expressly request that we begin providing the Service immediately and you acknowledge that you will lose your 14-day right of withdrawal once the Service has been fully supplied. This does not affect your other mandatory statutory rights.

Billing provider. Payments are processed by Stripe. We do not store your full card details. Your use of payment features is also subject to Stripe’s terms.

Except where a refund is required by applicable law (including EU/UK consumer rights, California and other mandatory consumer-protection laws), fees are non-refundable and there are no refunds or credits for partial periods.

As a courtesy and to honor our obligations, we will review good-faith refund requests — for example, a charge you did not intend after a trial, or a renewal you tried to cancel — if you contact support@rikai.ai promptly. Nothing in this section limits your non-waivable statutory rights.

You keep ownership of the decks, vocabulary, and other content you create or upload (your “Content”). You grant us a limited, non-exclusive license to store, process, transmit, and display your Content solely to operate the Service for you — including sending vocabulary you choose to AI features so we can generate the sentences, definitions, or meanings you request.

You represent and warrant that you have the rights necessary to upload your Content and to grant this license, and that your Content does not infringe any third party’s copyright or other rights or violate any law. Vocabulary copied from textbooks, apps, or other copyrighted sources may be protected; do not upload content you do not have the right to use.

AI-generated sentences, definitions, and multilingual meanings are produced by a third-party model provider (currently Google Gemini) and may be inaccurate, incomplete, or misleading. They are study aids only and are not authoritative translations or professional advice.

Do not rely on AI output for exams, academic submissions, legal, medical, financial, professional, or other consequential uses without independent verification (e.g., a dictionary, teacher, or professional translator). You use AI output at your own risk.

You acknowledge that AI features are subject to the provider’s terms and usage policies, and that on the free AI tier, content sent to the provider may be used to improve the provider’s models (see the Privacy Policy). Do not submit personal, sensitive, or confidential information to AI features.

You agree not to:

• upload unlawful, infringing, or rights-violating content;
• abuse, reverse-engineer, decompile, scrape, overload, or circumvent rate limits or security of the Service;
• use the Service to violate any law or any third party’s rights;
• use AI features in any way prohibited by the AI provider’s policies; or
• resell or provide the Service to others except as expressly permitted.

We may remove content and suspend or terminate accounts that violate this section, and we will terminate repeat copyright infringers (see Section 9).

We respect intellectual property rights. If you believe content on the Service infringes your copyright, send a notice to our designated agent at dmca@rikai.ai including: identification of the work, the infringing material and its location, your contact information, a statement of good-faith belief that the use is unauthorized, a statement that the notice is accurate and that you are authorized to act, and your signature.

We will respond to valid notices, remove or disable infringing material, and terminate repeat infringers. We will register a DMCA designated agent with the U.S. Copyright Office.

THE SERVICE IS PROVIDED “AS IS” AND “AS AVAILABLE”, WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. We do not warrant that the Service will be uninterrupted or error-free, or that AI output will be accurate or reliable. Some jurisdictions do not allow certain warranty exclusions, so parts of this section may not apply to you.

TO THE MAXIMUM EXTENT PERMITTED BY LAW, WE ARE NOT LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, OR LOSS OF DATA, PROFITS, OR GOODWILL. OUR TOTAL LIABILITY FOR ANY CLAIM IS LIMITED TO THE GREATER OF US $50 OR THE AMOUNT YOU PAID US IN THE 12 MONTHS BEFORE THE CLAIM.

Nothing in these Terms excludes or limits liability that cannot be excluded by law, including for fraud, willful misconduct, or death/personal injury caused by negligence. Some jurisdictions do not allow these limits, so they may not fully apply to you, and consumers retain their non-waivable statutory rights.

You must be at least 16 years old (or the minimum digital-consent age in your country, if higher) to use rikai. The Service is not directed to children under 16 and we do not knowingly collect their personal data. We may ask you to confirm your age at sign-up and may close accounts that do not meet the age requirement.

To the extent permitted by law, you agree to indemnify and hold us harmless from claims, damages, and costs arising out of your Content, your breach of these Terms, or your misuse of the Service.

You may stop using the Service and delete your account at any time. We may suspend or terminate access for breach of these Terms, to comply with law, or to protect the Service or other users. On termination, the license you granted us ends except for backups or records we must retain by law.

We may update these Terms. For material changes we will notify you in-app or by email and update the Version and Last updated date above. We will record your acceptance of the new version. Continued use after changes take effect means you accept them.

These Terms are governed by the laws of the State of California, USA, without regard to conflict-of-laws rules, and the exclusive venue for any dispute is the state and federal courts located in the State of California.

Questions: support@rikai.ai.