Shelflife is a single-file web app that tracks your skincare & makeup stash and flags what's expired, expiring soon, or still fresh — no spreadsheet, no printable checklist, no subscription. Pick from 100+ built-in product types for a shelf-life-after-opening estimate. Log the open date once and it does the math. Also tracks cost, brand & storage location, exports JSON/CSV backups, syncs to your calendar, and has full dark mode. Everything stays in your browser — no account, no server.