Excellent security checklist! I particularly appreciate that you emphasized layered security rather than presenting any single technique as a complete solution. Too often developers rely solely on HTTPS or obfuscation, but real application security comes from combining secure storage, backend validation, certificate pinning, integrity checks, and proper authentication.
I also liked the clarification about environment variables they're useful for configuration, but they shouldn't be treated as a secure place for secrets in mobile apps. That's a misconception many developers still have.
This is a practical guide that every Flutter developer should review before publishing a production app. Great work! 👏