LogN Terms of Use

1. Who offers LogN

• Legal name: JOSE CLEITON BORGES CORREIA (Brazilian sole proprietorship, "Empresário Individual")
• Trade name: CLEITON TECH
• CNPJ (Brazilian company registration number): 40.463.475/0001-39
• Address: Caminho das Árvores, 1057, Salvador Shopping Business, Torre América, salas 911 e 912, Salvador (BA), CEP 41.820-790, Brazil
• Contact: contact@logn.sh

In these terms, "we" means the party above, and "you" means the person using the app.

2. What LogN is

LogN is an app for competitive programming training. You solve challenges organised into trails, earn XP and unlock new nodes. The main trail is free; the other trails are paid, sold one by one (section 10). You can play without an internet connection: progress is kept on the device and sent to the server when a connection is available.

LogN is available in every country except those of the European Union, the United Kingdom and China.

3. Acceptance of these terms

At sign-up, you accept these terms and the Privacy Policy. We store the version and language you accepted, and when.

If you play as a guest, without an account, these terms also apply to that use.

4. Minimum age

To create an account, you must be 13 or the minimum age required by the law of your country, if higher. By ticking the age box at sign-up, you declare that you meet this requirement. If you are not that age, do not create an account.

5. Your account

• The account is personal. Do not share it or transfer it to anyone else.
• You sign in with an email address and password, and we confirm the email address with a code sent to it, or you sign in with Google, Apple or GitHub, who confirm the email address for us. Sign in with Apple is only available on iPhone.
• You are responsible for keeping your password secret and for what is done with your account.
• If you suspect someone is using your account, reset your password in the app (this ends all open sessions) and let us know at contact@logn.sh.

6. Guest mode

You can play without an account. In this mode, progress stays on the device only and is not sent to the server. If you delete the app or change devices, that progress is lost.

7. Acceptable use

By using LogN, you agree not to:

• use programs, scripts or any automation to answer challenges;
• attack, overload, probe or attempt to break into LogN's server or API;
• try to get around the limit on sign-in attempts, email codes or any other protection;
• forge or alter the progress records sent to the server;
• access another person's account.

If you break these rules, we may reject the affected records and suspend or close your account. Before suspending, we notify you at your account's email address, and you can appeal at contact@logn.sh. An attack on the server or the API may lead to immediate suspension, with the notice right after.

Closing the account for these reasons does not revoke a purchased trail: you can restore it to a new account, except in the cases of section 10.5.

8. Progress and XP

• Each answer sent to the server carries an integrity code linking it to the previous one. The server checks this chain and may reject records that fail the check.
• Each challenge earns XP only once per account.
• XP and progress have no monetary value and cannot be exchanged, sold or transferred.
• Some areas of the app may show sample data. When that is the case, the app says so.

9. Challenge content

The challenges, problem statements, answer keys and explanations belong to their authors. We grant you a personal, non-exclusive, non-transferable licence to use this content within the app: free for the main trail and for the first node of each paid trail, and purchased for the rest of the paid trails (section 10). You may not copy, republish, sell or distribute the content outside the app without permission.

Some of the problems come from the collection of Jorge Farias, professor at the State University of Bahia (UNEB), and are identified in the app with the origin badge.

The LogN name, symbol and visual identity are ours and may not be used without permission.

10. Paid trails

Besides the main trail, which is free, LogN offers paid trails, sold one by one inside the app.

10.1 What you buy

Buying a paid trail gives you a licence to use the content of that trail, personal, non-exclusive and non-transferable, inside the app and tied to your account. You do not buy the content, and the licence cannot be sold, lent or passed to another account.

• The first node of each paid trail is free, so you can get to know the trail before buying.
• Each purchase is a one-off, per trail. It is not a subscription, and there are no recurring charges.
• Updates to the content of a trail you bought are free of charge.
• You need an account to buy. Guests are taken to sign-up first.

10.2 Payment

Purchases are made through your device's store: Google Play on Android, and the App Store on iPhone. The store charges, processes the payment and issues the receipt, under its own rules: Google on Google Play, and Apple on the App Store. We do not receive your card number or any other payment data. The price of each trail is shown in the app before you buy. The stores' family sharing (Family Library on Google Play, Family Sharing on the App Store) does not apply to paid trails.

10.3 Refunds

Refunds are requested from the store you bought from, under its own rules. On Google Play, a request made in the first 48 hours after the purchase goes through Google Play itself. On the App Store, the request goes through the App Store itself. When the store approves a refund or a chargeback, the licence for that trail is revoked (section 10.5). Deleting your account does not give you a refund.

You can withdraw from the purchase within 7 days (right of withdrawal). On the App Store, the request is made at reportaproblem.apple.com. On Google Play, after the first 48 hours, write to contact@logn.sh from your account's email address, saying which trail, and we refund it through Google Play.

Nothing in this section excludes rights that consumer protection law grants you.

10.4 Offline use and devices

• A purchased trail can be downloaded and stored on the device, encrypted, to play without an internet connection.
• Without contact with the server, the trail opens for up to 30 days. After that, it asks you to connect the device, and opens again as soon as the app reaches the server.
• There is no limit on devices. We record which devices use the licence (Privacy Policy, section 3), to identify account sharing.
• If you delete your account and create another, "Restore purchases" links the purchase to the new account. A purchase is linked to one active account at a time.

10.5 When the licence is revoked

We only revoke the licence for a paid trail in these cases:

1. a refund or chargeback of the purchase, approved by the store;
2. fraud in the purchase: a transaction that fails verification, or that the store flags as fraudulent;
3. redistribution of the content: publishing or passing on, outside the app, the trail's problem statements, answer keys or explanations;
4. account sharing: the same account used at the same time on devices of different people. The evidence comes from the device record and only considers devices active in the same period, not reinstalls or a new phone.

In cases 3 and 4, we revoke the licence ourselves and keep the evidence. Right after revoking, we notify you at your account's email address, with the reason, and you can appeal at contact@logn.sh.

We confirm that we received the appeal and answer within 5 days. In the case of account sharing, the licence comes back while we review it. If the appeal is accepted, the licence is restored, with your progress.

We do not revoke a licence without one of these reasons. A trail that is no longer sold keeps opening for those who bought it.

10.6 After revocation

• The XP you earned on the trail stays in your level.
• Your progress on the trail is kept, and the trail stops opening. The copy on the device is deleted the next time the app reaches the server.
• If the licence comes back, through a new purchase or a restore, the progress comes back with it.

10.7 Content protection

A downloaded trail is stored encrypted on the device. This protects against simply copying the file: it does not stop someone with full control of the device from extracting the content, and extracting it to pass it on is redistribution (section 10.5).

11. Availability and changes to the service

We work to keep LogN running, but failures, interruptions and data loss can happen, including because our database has no backup copies. If the database is lost, purchases come back through "Restore purchases", because the store you bought from also keeps a record of them; accounts and progress do not come back. We may change, suspend or discontinue features or the service itself. If we decide to discontinue the service, we will let you know in the app and at your account's email address at least 90 days in advance.

Before shutting down the server, we will publish a version of the app in which purchased trails open with no time limit and no connection.

12. Deleting your account

You can delete your account at any time inside the app, under Manage account. The account is deactivated immediately, and you have 30 days to change your mind: just sign in or reset your password during that period. After that, the data is erased permanently, within 31 days of the request. The Privacy Policy (section 10) explains what is erased and what stays outside the database.

13. Liability

To the extent permitted by applicable law, we are not liable for indirect damages caused by use of the app, nor for loss of progress that had not yet been sent to the server. Nothing in these terms excludes rights that consumer protection law grants you and that cannot be excluded by contract.

14. Changes to these terms

When we change these terms, we will publish a new version with a new effective date and let you know in the app. If the change is significant, we will ask you to accept the new version in the app before you continue using your account. If you do not accept, you can delete your account. A new version does not change the conditions of the trails you already bought: they stay as they were in the version under which you bought them.

15. Language, governing law and jurisdiction

These terms exist in Portuguese, English and Spanish. If the versions differ, the Portuguese version prevails.

These terms are governed by Brazilian law. The courts of the judicial district of Salvador (BA), Brazil, are chosen as the forum. If you are a consumer and the law of your country or Brazilian law gives you the right to go to court where you live, or to have local consumer law applied, that right still applies.

16. Contact

Questions about these terms: contact@logn.sh.