Business Card Tap is an Android-only digital business card app. The user enters their own contact details once (name, job title, company, phone, email, website, Instagram/LinkedIn/X/WhatsApp handles). The phone then acts as an NFC business card via Host Card Emulation (NFC Forum Type 4 Tag): tapping the phone against another phone transfers the card as a vCard instantly — the receiving phone needs no app. A QR code of the same vCard is always shown on screen as a fallback for phones without NFC (any smartphone including iPhone can scan it and save the contact). The app is fully offline: no account, no sign-up, no backend server — all card data is stored only on the device (localStorage). Users can create multiple card profiles (work / personal / side project) with labels. Monetization: free version shows banner and interstitial ads via Google AdMob (with a first-launch consent screen offering personalized or limited/non-personalized ads, Google UMP on device); in-app purchases via Google Play Billing: a one-time "Remove Ads" purchase ($2.99, product id tapkart_noads) and a weekly "Premium" subscription ($4.99/week, product id tapkart_premium_weekly) which removes ads and unlocks multiple card profiles. A "Restore Purchases" option exists. Permissions used: INTERNET (ads + remote config only), NFC (solely to emulate a contactless business card while sharing; never reads payment cards, never scans tags in the background). The app fetches a small remote configuration file (feature flags/announcements) that contains no personal data. General audience productivity app, not directed at children. UI available in 8 languages (EN default, TR, DE, ES, FR, IT, PT, AR).