Simplifies comparing photos of tamper-evident seals and patterns using your eyes

go to github download

Blink Comparison

Simplifies comparing photos of tamper-evident seals and patterns using your eyes.

Get it on F-Droid
Get it on Google Play
Get it on GitHub
Get it on Android File Host
Direct APK Download

Current version
Made with Flutter
Matrix Room
Chat - Telegram



The concept of “blink comparison” method is simple - the app allows you to quickly switch pictures without delay so you can see the differences.

“Blink comparison” (Wikipedia) method uses high efficiency pattern recognition by human eyes, to permit quick verification between a reference picture and an actual one being taken on the spot. For example, in the goal of detecting tampering in high contrast nail polish tamper-evident seals.

Relative documentation on the tamper-evident glitter nail polish seals concept and why it is hard to beat:

Use, see, change and share; with all.

📋 Features

  • Free and Open Source software (FOSS)
  • Support for various platforms and devices (currently Android only)
  • Add and store reference pictures in the app or take a photo on the spot; all pictures are encrypted, making it harder to steal or replacement
  • Compare a reference image with the one just taken using “blink comparison” method
  • Helps to take a compared photo in the correct position, at the correct angle, lighting and distance
  • Material Design
  • Night theme
  • Responsive UI for different devices form factors

🔒 Security

All reference images that added to the app stored as encrypted, making it harder to steal or replacement. Currently, password-based encryption (PBE) is used. It’s based on the XChaCha20Poly1305 scheme and using a key derived by Argon2 function “on the fly” (during the encryption/decryption itself). The password is stored in the app as a hash obtained with Argon2.

🖥️💻📱 Available platforms

  • Android
  • iOS (planned)
  • Linux (planned)

🌍 Translations

  • English
  • German
  • Russian
  • Spanish (thanks andgar2010)
  • French (thanks BNouailhac)

💰 Donation

If you like Blink Comparison you can support developer with these methods. If you have problems with payment or you want to donate in another way, contact me: Thank you!

  • PayPal: paypal
  • Yandex Money (YooMoney): 410011738561939
  • WebMoney:
    • WMZ: Z335461926163
    • WMR: R151579576467
  • eGift Cards: just choose your amount and type e-mail
    in the gift card details
  • Liberapay: liberapay
  • Bitcoin: 1Af9DgxtWvVp6bFiYQw2MeWtRzTXshRYpB
  • Nano: nano_1jtaa1njf3pn66pi48uqbak3rpbn373px6xeugynwxm1yb5hyfb6ure15pyy
  • Monero: 48j4Mo7J7t51EeBf35Lpdmehmi9chUwzSXxHrnjpRJ6fPQafPWvSCdFafw3rA5ZRWievfYEDToNso8VppbJf2RVH9cdZmHa

⚙️ Building

Please see

🎉 Contributing

Please see



🔒 Privacy Policy

Please see our Privacy Policy.

📄 License

Large GPLv3 logo with “Free as in Freedom”

Copyright (C) 2022 Yaroslav Pronin <>
This file is part of Blink Comparison.
Blink Comparison is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program.  If not, see <>.

excellent projects related to proninyaroslav/blink-comparison recommend downloading