A smart Android application built in Java that functions as a fully working standard calculator while secretly operating as a secure vault to hide and protect personal files such as photos, videos, audio, and notes. It fulfills client requirements by providing password protection, hidden storage management, and a disguised privacy-focused interface. The project demonstrates expertise in secure data handling, multi-activity navigation, Android storage APIs, and modern UI/UX design, built with a focus on clean architecture, performance, and user confidentiality.