Terms of service

Effective October 1, 2026

Who runs STREN

The STREN app and the stren.world website are run by the app's developer. For anything, including content reports and complaints, write to [email protected] in Polish or English. This is also our point of contact for users and authorities under the Digital Services Act (DSA).

What STREN is

STREN is a training log: sets and measurements, a plan with streaks, an exercise atlas, a gym map, a battle pass and badges, an AI coach and a social feed. These terms explain how to use it. What happens to your data is described in the privacy policy.

Agreement and account

The agreement starts when you start using the app, and you can end it at any time by deleting your account (Settings → Delete account) and the app. Using STREN is free. You create an account with your email (you sign in with a code sent by email), with Google or with Apple; you need it for the AI coach and to add photos. Keep your mailbox secure, because it is the key to your account.

STREN is for people aged 16 and over.

Technical requirements

You need a phone with a version of iOS or Android listed in the store, and the app downloaded from the App Store or Google Play. The log works offline; the account, AI coach, map and exercise animations need an internet connection.

Community rules

In the social feed (nickname, posts, photos, comments) you may not publish:

• illegal content,
• nudity or sexual content,
• blood, injuries or violence,
• encouragement of self-harm, eating disorders or doping,
• hate speech, harassment or threats,
• other people's data or images without their consent,
• content you do not have the rights to,
• spam, advertising or impersonation.

Before publication, photos are checked automatically by an AI model (details in the privacy policy). Automated checks can be wrong, so you are responsible for what you publish.

By publishing content you grant us a free, non-exclusive licence to store it and show it to other STREN users, to the extent needed to run the app. The licence ends when you delete the content or your account.

Reporting content and account blocks

Report content that breaks the law or these rules in the app (hold a post → Report) or by email to [email protected]. In the email, tell us where it is (author's nickname, date, screenshot) and why it is not allowed, give your name and email, and confirm that you are reporting in good faith. You do not have to give your name when reporting child sexual abuse. We handle reports without undue delay and reply with our decision.

We remove or hide content that breaks the rules, and for serious or repeated violations we block the account. We tell the author why, unless the law forbids it. You can appeal a decision by replying to the message about it; appeals are reviewed by a person.

You can also block anyone: hold their post or use the button at the bottom of their profile. You will no longer see their posts or comments, and in rankings their place will show “Blocked”. You can see and undo blocks in Settings → Blocked users. We are notified of every block so we can check whether something serious is going on.

AI coach

The coach's answers are written by an AI model (Claude by Anthropic). They may be inaccurate or wrong, so treat them as tips, not medical advice. Do not tell the coach anything you do not want to share, such as information about illnesses. The number of messages per day is limited; we may change the limit and the model.

Health and safety

STREN is not a medical device and does not replace a doctor, physiotherapist or coach. Estimates in the app (such as body fat) are approximate. Before you start training, especially with health problems, during pregnancy or after an injury, talk to a doctor. Stop exercising if you feel pain, dizziness or shortness of breath.

Payments

Today all STREN features are free. If we introduce paid features (such as a subscription or a paid battle pass track), these rules will apply:

• before you buy, you will see the price including taxes, the billing period and what you get,
• payment, receipts and refunds are handled by the App Store (Apple) or Google Play under their terms; we never see your card details,
• a subscription renews automatically until you cancel it in your Apple or Google account settings, and stays active until the end of the paid period; deleting the app or your STREN account does not cancel a subscription,
• as a consumer you can withdraw from a distance contract within 14 days without giving a reason; you do this in the store where you bought. If you ask for access before the 14 days are up, on withdrawal you pay for the time you have already used; for digital content delivered immediately with your express consent and your acknowledgement that you lose this right, the right of withdrawal expires,
• battle pass rewards are known in advance, with no paid random draws; virtual items have no monetary value and cannot be exchanged for money or transferred to another account,
• the store will notify you of any subscription price change; if you do not agree, you can cancel.

Rights to the app

The app, its design, code and content belong to us or our licensors (exercise animations: © Gym visual, used with permission; exercise data: MIT licence). You may use them in the app for your own non-commercial purposes. You may not copy them outside the app, bulk-download data from our server, or bypass limits and security measures.

Availability and liability

We try to keep STREN running without interruptions, but the server may sometimes be unavailable, for example during updates. We may develop and change features; we will give notice before removing an important one. Your log is stored only on your phone, even if you have an account: we keep no copy, so deleting the app or losing your phone means losing your log.

Our liability is governed by Polish law. Nothing in these terms limits the rights you have as a consumer by law.

Complaints

If STREN does not work as described, write to [email protected]: describe the problem and give your phone model and app version. We will reply within 14 days. Payments and refunds are handled by the store where you bought.

As a consumer you can also use out-of-court dispute resolution. In Poland, help is available from municipal and district consumer ombudsmen and the Trade Inspection (uokik.gov.pl); in other EU countries, from the European Consumer Centre in your country.

Changes to these terms

We may change these terms for important reasons: changes in the law, new or changed features (such as paid ones), store requirements or security. We will announce changes in the app or on this page at least 14 days in advance, unless the law or security requires a faster change. If you do not agree, you can delete your account and the app at any time.

Governing law

These terms are governed by Polish law. If you are a consumer from another country, you keep the protection given to you by the mandatory laws of your country. If language versions differ, the Polish version prevails.