Calculator - SecureVault

CodeHorizon

About this app

Calculator – SecureVault: Scientific Calculator with Zero‑Knowledge Secure File Vault

Turn your Android device into a dual‑purpose tool: a full scientific calculator on the surface, and a deeply secure, offline file vault underneath.

-- POWERFUL CALCULATOR
• Complete scientific calculator: trigonometric, logarithmic, exponential, percentage, and power functions
• Real‑time expression preview with correct order of operations and parentheses support
• Calculation history with easy swipe‑to‑delete and one‑tap result reuse
• Quick copy of results to clipboard and auto‑scaling display for long expressions

-- STRONG, LOCAL‑ONLY ENCRYPTION
• AES‑256‑GCM file encryption for photos, videos, documents, and any other file type
• Encryption keys protected by Android Keystore with hardware‑backed storage where available
• Zero‑knowledge design: only your passcode/biometrics can unlock files, never stored in plain text
• Configurable 4–8 digit passcode plus optional biometric unlock (fingerprint/face, depending on device)
• Hidden calculator trigger code to open the vault from the normal calculator interface

-- PRIVACY & STEALTH FEATURES
• Optional protections: hide from recent apps and block screenshots in sensitive screens
• Automatic return to the calculator UI to keep the vault hidden in plain sight
• Encrypted filenames and metadata so contents can’t be guessed from file names
• Local‑only storage: no cloud sync, no external servers, and no third‑party analytics

-- SECURE FILE MANAGEMENT
• Import and encrypt existing photos, videos, documents, and other files into secure folders
• Organize content with folders and intuitive file actions inside the encrypted space
• Fast, on‑device decryption when you open files; re‑encrypted immediately when you’re done
• Auto‑lock after inactivity so the vault closes even if you forget

-- MODERN, ACCESSIBLE DESIGN
• Clean Material Design 3 interface with dynamic colors that adapt to your system theme
• Light and dark modes, smooth transitions, and attention to readability
• Optimized layouts for one‑handed use and larger displays

-- 100% OFFLINE, ZERO DATA COLLECTION
• Works fully offline – no account, no registration, no network required
• No tracking, analytics, or hidden connections: the app does not send your data anywhere
• All encryption and decryption happens entirely on your device

-- PERMISSIONS
• Storage / media access: used only to encrypt and decrypt files you select
• Biometric: used only to unlock the vault as an alternative to your passcode
• No internet or location permission required

Ideal for students, professionals, and privacy‑focused users who want a capable calculator on the surface and a secure file vault underneath.

Important: If you forget your passcode and recovery options, your encrypted files cannot be recovered. Always keep separate backups of irreplaceable data.

What’s new

What’s new in 6.0
- App is now fully compatible with the latest Android versions and Google Play’s new 16 KB page-size rules.
- Improved internal security handling so encryption stays fast, safe, and reliable on new devices.
- Added an offline recovery option with a security question and hint to help you safely regain access.
- Better support for fingerprint and microphone features on modern Android phones.