Account and app terms
Release date: 2026-12-01. This address always shows the current terms; the release date is the version you accept.
1. Who we are
Osilera is a product of D4 Dijital Çözümler A.Ş., Hüseyinağa Mah. İstiklal Cad. GrandPera No:56-58 İç Kapı No: 5, Beyoğlu, İstanbul, Türkiye, tax number 2650762428 (Beyoğlu Tax Office), MERSİS number 0265 0762 4280 0001 ("D4", "we"). In these terms "Osilera" means the Osilera Survey app, Osilera Web and the services behind them, which D4 provides. Contact: support@osilera.com.
2. Your account
You create an account by signing in to the Survey app with Google, Apple, Microsoft or an email address and a password, and by accepting these terms. The account is yours alone: it has its own space in Osilera (your personal account) that nobody else can join. You may add other ways to sign in to the same account and remove them, keeping at least one. Give us correct information and keep your sign-in secure; you are responsible for what is done with it.
You must be at least 18 years old and use Osilera for professional purposes.
3. Teams and companies
You may join a company's team by accepting its invitation, or ask for a team of your own, which D4 or its channel partner switches on. Inside a team, the team's administrator decides who may do what, and the company's own agreement with D4 or its channel partner applies to the team's data. A team's administrator may block your app access to that team's data; that does not affect your other teams or your personal account. D4 may block an account everywhere in the cases listed in section 10.
4. Your readings
Readings you take are kept on your phone, locked with a key that belongs to your account. A reading taken for a team's machine is sent to that team and belongs to that company. Readings of your own are copied to your personal account only while you hold the backup subscription; without it, your phone and the exports you make are their only copy, and D4 cannot restore them. You can export your readings from the app at any time.
5. Sensors
To connect an Osilera sensor, the app fetches that sensor's connection key from Osilera; any signed-in person may do so. D4 records which accounts and teams used which sensor and when (first and last use), to protect against misuse and to support you; only D4 staff see this record. You may register a sensor you are entitled to use to yourself or to your team with one tap; a registered sensor gives the app's features to its holder. A sensor you use without registering it gives them for 24 hours after it disconnects. A sensor reported lost or stolen to D4 with proof of purchase receives no new keys. Registering a sensor does not transfer ownership of the device, which follows its purchase.
6. Features, subscriptions and purchases
Which features of the app you can use is decided by Osilera from: a sensor registered to you, your team's edition and add-ons, or a subscription or add-on you bought. Without any of these you can open the demo cases. When a right ends, you keep opening and exporting your own readings and the results already computed; new analyses need the right again. Purchases made in the App Store or Google Play are governed by that store's terms, including renewals and refunds. Prices and terms are shown in the store before you buy.
We work to keep Osilera available but cannot promise it will never be interrupted; readings already on your phone stay available to you. We may change features, and we tell you in the app before a change removes something you rely on. A company's service levels are in its own agreement.
7. Demo cases
The demo cases are anonymised public datasets for learning the app. They are not your data, and readings from them are never sent to a team.
8. Analyses are guidance
The app's diagnoses, grades and advice help a trained person judge a machine's condition. They are not a guarantee that a machine is safe or will not fail, and they do not replace the judgement of a qualified person or the maker's instructions. Osilera is not a machine-protection or safety system and must not be the only means of protecting people or equipment.
To the extent the law allows, D4 is not liable for indirect or consequential loss, such as lost production, lost profit, downtime or the cost of a machine failure. Nothing in these terms limits liability that the law does not allow to be limited, in particular for intent or gross negligence (Turkish Code of Obligations No. 6098, Art. 115) or for death or personal injury, or the rights that consumer law gives you.
9. Licence and fair use
D4 licenses the app to you, it does not sell it: you may use it for your professional purposes while your account exists, and you may not transfer that right. The app, the sensors' firmware and keys, and the Osilera name and logo belong to D4 or its licensors. Your readings stay yours, or your team's company's; you give D4 only the right to process them to provide Osilera, as the app privacy notice describes.
Do not try to break into Osilera, read others' data, copy or reverse-engineer the app or the sensors' keys, collect sensor keys in bulk, or use Osilera against the law.
10. Blocking and ending
D4 may block an account that breaks these terms, puts others' data at risk, or as the law requires; we tell you why unless the law forbids it. You may delete your account at any time, in the app (Settings > Account > Delete account) or at osilera.com/account/delete. Deleting it removes your sign-ins at once, ends your memberships, and deletes your personal account within 30 days. Your records in the app are cleared on the phone where you delete the account, and on your other phones the next time they connect to Osilera. Readings you sent to a team stay with that company, marked as taken by a deleted person with no name, and the record of sensor use keeps no name. Before it clears anything the app offers to back up all your data to a file you keep; D4 cannot recover what is cleared.
11. Product news
Product news by email is a separate choice you make at registration and can change at any time in the app. Messages about your account and its security are sent regardless.
12. Changes to these terms
We publish each new version at this same address with its release date and tell you in the app. The app asks you to accept a new version at its next opening; you can keep working meanwhile. A new version applies to you once you accept it. If you have not accepted it 30 days after we told you, we may limit your use of the app to opening and exporting your own readings until you accept; you can always export your readings and delete your account. A change the law requires applies from the date the law sets.
13. Privacy
How we handle personal data is in the app privacy notice.
14. Law and courts
These terms are governed by the laws of the Republic of Türkiye. The courts and enforcement offices of İstanbul (Çağlayan), Türkiye, have jurisdiction. Where you are a consumer, the consumer courts and consumer arbitration committees that the law makes competent remain available to you.