calc+ for Android

calc+ is a secret photo vault and calculator lock app for Android. It looks and works like a regular calculator — so your hidden photo vault is completely invisible on your phone.

How to hide photos on Android with calc+

Install calc+ from Google Play, choose your secret vault PIN, then import photos and videos from your Android gallery. After import, you can delete the originals — your media now lives only inside calc+'s encrypted vault, accessible only through the calculator PIN you set.

Built for Android

• Fingerprint unlock — supports Android biometric authentication to open your device before accessing the calculator
• No Google Drive sync — vault contents never leave your Android device; no cloud uploads
• Android gallery integration — import directly from your photos and gallery apps; originals can be deleted after import
• Screen recording prevention — Android FLAG_SECURE prevents screenshots and screen recording while the vault is open
• Background lock — vault auto-locks when the app is backgrounded or the screen turns off
• Works on phones & tablets — supports all modern Android devices

Military-grade encryption on Android

Every file stored in calc+ is encrypted with AES-256-GCM before being written to your Android device's storage. Keys are derived using PBKDF2-SHA256 (100,000 iterations) with a unique salt per vault, and the app-level pepper is stored using Android's Keystore system — hardware-backed key storage on supported devices.

Completely offline

calc+ makes zero network requests. No Google account required, no server, no cloud. Your hidden photos never leave your Android device.