Renewal Reminder
A free subscription tracker built so privately that no PII leaves the device. Universal-pain framing.
Renewal Reminder is the privacy-first subscription tracker. The opening copy is direct: Subscriptions sneak up on everyone. That is the whole app. No account, no bank link, five free renewals before Pro.
The implementation is acquisition-grade. Eight production security headers including HSTS preload-eligible (max-age two years), full Content-Security-Policy with Stripe and Iubenda allowlists, frame-ancestors none, COOP plus CORP same-origin. WCAG 2.1 AA across every screen — prefers-reduced-motion guards, ARIA-modal dialogs, full keyboard support, Esc-key dismiss on every overlay.
Code-split rare-path screens (Welcome, Paywall, AddEdit, Settings, Legal) keep the initial JS bundle at 115 KB gzip. Five ADRs in docs/adr govern the no-account, PWA-first, localStorage-then-Supabase decisions. Top-level ErrorBoundary, Web Push receiver scaffold, Stripe webhook stub with hand-rolled HMAC verify — all production.