I want a fully-functional calculator that looks and behaves exactly like a normal, basic calculator until I key in a secret passcode. At that moment the interface should slide (or otherwise transition smoothly) into a private gallery where I can import, play, and manage all of my personal videos. The build needs to run natively on both iOS and Android, so please rely on a shared codebase—Flutter or React Native are both fine, as long as you can meet App Store and Play Store guidelines. Security is crucial: once inside the hidden area, users must still authenticate with the same numeric password they used on the calculator screen. Fingerprint or Face ID support is optional for the first version; simple password protection done well is my priority. Visually, I’m after an ordinary, no-frills calculator layout: standard buttons, basic colours, nothing that would hint at a vault behind it. Icons, animations, and any text in the hidden gallery should also stay minimal so the disguise never looks suspicious. Deliverables • Source code and project files for both platforms • A compiled IPA and APK ready for TestFlight / internal testing • Brief documentation that covers build steps, password reset flow, and any libraries used I’ll test by importing several HD videos, locking the app, and confirming they remain invisible everywhere else on the device. If that works flawlessly and the calculator performs normal arithmetic without lag, the job is complete.