1. Provider, scope and acceptance
Provider: WENYU SUN ("we").
Location: Tokyo, Japan. Legal and support contact: ewanesun@gmail.com.
Version: 2026-10-16-1. Effective for you when you accept this version. App version: TETSU 1.0. Distribution territories: Japan, the United States and all 27 European Union member states, subject to App Store availability.
These terms explain the conditions and risks of using TETSU. Read and expressly accept them before enabling restrictions. If you disagree, do not enable new sessions or schedules. Reading information, declining terms or cancelling a confirmation does not start a block. Acceptance does not waive your legal rights or replace Apple's Screen Time authorization.
The software is licensed under the Apple Standard EULA. This document explains TETSU-specific usage conditions and risks; it does not replace that license or Apple's purchase terms. Mandatory consumer rights take priority.
2. Eligibility and voluntary use
TETSU is for adults with the legal capacity required where they live, voluntarily managing a device they are entitled to control. Do not impose restrictions on a device without authority, or use TETSU to coerce, monitor or punish another person or obstruct their access to help.
This version does not provide child supervision, employee management or a way to consent on another person's behalf. An App Store content rating is separate from legal eligibility to enter this agreement.
3. What TETSU provides
TETSU is an iPhone focus tool using Apple's Screen Time features to restrict selected apps, categories and websites. This version supports manual sessions of 15 minutes to 12 hours, one recurring weekday schedule, and an early-exit process requiring a 15-minute wait followed by confirmation.
It operates on the device without a TETSU account, developer backend, cloud sync, subscription or in-app purchases. It does not block other devices or provide daily usage budgets, a third-party PIN or remote supervision. Make arrangements using features actually available in your version.
4. Your settings and conduct
Decide whether restrictions are appropriate for your circumstances. Check the selected items and categories, duration, weekdays, start and end times, and displayed time zone. First try a short session with a nonessential app in a safe setting. Check essential access and an alternative way to communicate before using longer sessions or automatic schedules.
You are responsible for choices and conduct reasonably within your control, including lawful use and respect for others' rights. Liability for harm attributable to your intentional or negligent conduct is determined by applicable law, causation and responsibility. This does not transfer our responsibilities or another party's responsibilities to you, or require you to cover every accident or third-party claim.
5. Essential access and possible consequences
Keep tools needed for urgent communication, medical care, caregiving, authentication, password access, payments, banking, travel tickets, navigation, building access and essential work available. Blocking them may cause missed messages, inability to sign in or pay, or delays to travel, work or care.
A whole category can include services you did not consider individually. This version has no configurable essential-app exception list and does not decide which tools are essential for you. Do not assume an app remains accessible just because you did not select it individually.
Do not configure restrictions that could obstruct necessary access while driving, operating equipment, on call, providing care or in another safety-sensitive situation. Arrange a way to seek help that does not depend on TETSU's exit process.
6. Fixed rules, schedules and early exit
During an active session or schedule window, the selection and related rules cannot be freely weakened within TETSU. In-app data reset is also restricted. Schedules use the time zone displayed and saved in TETSU; overnight windows belong to the weekday on which they start. Check them after travel or a device time-zone change. Saving or re-enabling a schedule that covers the current time may apply restrictions immediately.
The feature labelled "Early exit" is a delayed early exit. Restrictions continue throughout its 15-minute wait. Afterward, return to TETSU and confirm: a zero countdown does not automatically release the block. This is not immediate unlocking or emergency assistance.
Confirmation covers only the session and schedule window active when you requested that exit. Restrictions starting afterward are not covered; future scheduled windows remain enabled. Schedule editing can remain fixed until the original window ends, even after that occurrence's block is released. A commitment reaching its normal end follows its original rules; other overlapping restrictions may remain.
These times describe TETSU's rules. Actual enforcement and release are subject to the system limits in section 8, without a guarantee of exact timing.
7. Actual emergencies
For an immediate safety or medical emergency, do not wait for TETSU's countdown or a support reply. Seek local emergency help through an available system emergency-calling option, another phone/device or someone nearby.
TETSU does not detect emergencies, contact responders or guarantee that any particular app, network or communication channel is available. We cannot remotely unlock your device. Learn your device's own emergency options and their location, connection and setting requirements beforehand. See Apple's emergency-calling guidance.
8. Technical limitations and failures
Restrictions may fail to start, end early, release late, or be interrupted or prolonged. Causes can include TETSU or iOS errors, updates, restarts, permissions, clock or time-zone changes, background scheduling, other Screen Time rules and storage problems. Registration or a running timer does not establish that TETSU has independently checked every selected app's real access state.
TETSU cannot prevent its device owner from revoking individual authorization, removing the app, using other devices or exercising system controls. Do not rely on it as an unbypassable security boundary, your only dependable reminder, or a guarantee of work, study, financial or safety outcomes.
If behavior is wrong, stop relying on new blocking arrangements, secure necessary access, check TETSU and iOS settings, and follow the support instructions. iOS determines the effects of permission revocation and app removal; neither is a promise of instant recovery of all access.
9. No medical service or promised outcome
TETSU does not provide diagnosis, treatment, counselling or emergency care, or promise improvement in any illness, addiction, attention condition or specific productivity result. If a restriction causes significant distress or interferes with necessary care or communication, stop using that arrangement and seek suitable assistance when needed.
10. Lawful use, intellectual property and other services
Follow applicable law and the valid terms of the Apple, carrier, workplace and other services you use. Do not use TETSU for harassment, coercion, unauthorized restriction of another person's device or infringement of rights.
The software, design, name and materials belong to their respective rights holders. Using TETSU does not transfer ownership. Permission to use, copy or modify software follows the applicable license and law. Separate open-source licenses, where present, govern their components; nothing here prohibits conduct that law does not allow us to prohibit.
11. Price, purchases and refunds
Any download price is the price the App Store shows you at purchase. These terms do not promise a free or permanently free app. TETSU 1.0 has no subscription, trial converting to payment, in-app purchase or early-exit fee.
If you paid to download TETSU, you may request a refund through Apple's applicable purchase and refund process. Eligibility depends on the transaction, applicable conditions and law. This does not exclude rights you may assert directly against the provider and is not a blanket refusal of refunds. Future paid features require clear disclosure and any necessary agreement; accepting these terms does not itself authorize new charges.
12. Privacy, records and deletion
See the Privacy Policy. Acceptance of these terms is not blanket permission for undisclosed tracking, analytics or data use.
TETSU stores your selected Screen Time tokens, session and schedule rules, early-exit requests, setup completion, the latest scheduling callback and its time, and your terms acceptance record (version, text digest, time and language) on this device in storage shared with its extensions. The app does not send these focus records to us. In-app reset is available outside an effective lock; an original schedule window can keep reset unavailable. Revoking Screen Time access does not itself erase records. App removal, device backups and restoration follow iOS behavior and your settings. We cannot access or restore those local records for you.
Email, screenshots and diagnostics you voluntarily send to support, and connection data from the support website, are handled separately under the actual providers, purposes and retention periods in the published policy. Do not send passwords, verification codes or unnecessary sensitive information.
13. Assurances and responsibility
Where law permits, we give no additional guarantee of uninterrupted, error-free, precisely timed or unbypassable operation, or of a particular personal result. Describing risks does not permit us to ignore known defects, mislead users or avoid legal duties of care, disclosure or repair.
These terms do not exclude or limit our liability for fraud, intentional misconduct or gross negligence. They also preserve liability and remedies for personal injury, consumer rights, refunds, privacy and other matters that law does not allow us to restrict. Other liability and recoverable losses depend on applicable law, valid license terms and the facts. A loss is not automatically excluded merely because it concerns a missed message, lost data or business interruption.
This supplement adds no monetary cap, blanket exclusion of indirect losses or requirement to abandon all claims. Any proposed additional limit requires review for the actual distribution markets.
14. Support, updates and ending use
Send questions, complaints and rights requests to the contact in section 1. Practical guidance is available on the Support page. Support is not an emergency service, has no guaranteed immediate response and cannot remotely clear restrictions. Legally required support, fixes and remedies still apply.
We may update TETSU for fixes, compatibility or legal requirements. Material changes affecting existing rights or the end of maintenance remain subject to applicable notice and remedy obligations. These terms do not reserve an unlimited right to remove paid functionality.
You may stop using TETSU. Ending use or a contract is separate from TETSU's early-exit action: address existing restrictions and future schedules or use available iOS controls. There is no remote TETSU account to suspend or delete.
15. Changes to these terms
The version and when it takes effect are stated in section 1. We will give clear notice before material changes to rights, responsibilities or risks apply, and seek renewed agreement when law requires. Changes will not retroactively remove existing claims or treat silence alone as acceptance.
Reading existing rules, accessing safety information and completing an existing exit process must not depend on accepting new terms. New features or blocking arrangements may require the appropriate agreement first.
16. Law, disputes and languages
This supplement does not select an additional exclusive forum or require arbitration. It does not change the applicable law or dispute provisions of the Apple Standard EULA, or restrict mandatory consumer remedies, including any right to seek remedies where you live. Contacting support can help resolve a dispute but is not a compulsory prerequisite to exercising statutory rights.
The English and Japanese versions describe the same usage conditions and risks. Neither version reduces protections or language rights that mandatory law provides.
17. Individual provisions
Applicable law determines the effect of an invalid or unenforceable provision and whether the remainder continues. This does not make unfair exclusions valid or give us unilateral authority to decide liability or the final interpretation of these terms.