ZeFirst: Proof of Existence
Prove you were first
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Ready for iPhone Duo: open it, your file on one side, your proof on the other. Timestamp a photo or any file in 30 seconds, without ever uploading it.
An idea, a design, a manuscript, code, an invention… The day you have to prove you were first, what do you do?
With ZeFirst, in about thirty seconds you get a proof timestamped to the second that nobody can alter, erase or backdate – not even us.
READY FOR IPHONE DUO
Open it and ZeFirst switches to two columns: your file on one side, your proof on the other. Drag a photo from Photos or Files and it is timestamped as is. Closed, everything fits on the outer display. Also on iPad.
HOW IT WORKS
• Pick a file: document, image, code, audio, any format.
• Your device computes its digital fingerprint (SHA-256): 64 unique characters that can't be reversed.
• Your file never leaves your device. Only the fingerprint is sent.
• ZeFirst records it on a public blockchain, with the exact date and time.
• You get a PDF certificate with a QR code and a verification link to share.
VERIFIABLE WITHOUT US
Every proof carries its references: network, contract, transaction and a link to the public explorer. Anyone can re-verify it from your file, even if ZeFirst disappeared one day.
WHO IS IT FOR?
Writers, creators, designers, developers, inventors, photographers, musicians, students, founders: anyone who shares files and wants to be able to say "this was mine, first".
EVERYTHING YOU CAN DO
• Create a proof of prior existence in a few taps
• Verify a file or a fingerprint, even without an account
• Find all your proofs in "My proofs"
• Download your PDF certificate, with QR code
• Share a verification link
• Co-ownership: record a proof together, with each person's share
• Back up access to your account so you never lose it
• 5 languages, light or dark theme
SIMPLE, NO CRYPTO
Sign in with your e-mail (a one-time code), with Apple or with Google. No password, no cryptocurrency to buy: blockchain fees are on us. Your first 2 proofs are free. After that, refer a friend or buy credits in the app (1 credit = 1 proof).
Your account also works on the web, at zefirst.app.
Good to know: ZeFirst proves that a file existed, exactly as it is, on a given date. It is not a patent or trademark filing. Tip: record your file before sharing it, and keep the original untouched.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
• New: ready for iPhone Duo. Opened, ZeFirst switches to two columns (the file and its deposit, your proofs and their details), and a photo can be dragged straight from Photos or Files. Also on iPad in landscape.
• New: timestamp a photo in one tap. "Choose a photo" or "Take a photo": the original is timestamped as is and kept in the Files app, ready to prove (move-in inspection, damage, rental…).
• Updated Terms of Service.
• Fixes and improvements.
The developer, LGM CONSEIL LTD, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Purchases
- Contact Info
- User Content
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- LGM CONSEIL LTD
- Size
- 3 MB
- Category
- Productivity
- Compatibility
Requires iOS 26.2 or later.
- iPhone
Requires iOS 26.2 or later. - iPad
Requires iPadOS 26.2 or later. - Mac
Requires macOS 26.2 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.2 or later.
- iPhone
- Languages
English and 4 more
- English, French, German, Italian, Spanish
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- 1 credit $0.99
- 10 credits $3.99
- Copyright
- © 2026 LGM CONSEIL LTD