pwa

## What I do - Build installable web apps - Implement offline functionality - Create service workers - Configure web app manifests - Handle background sync ## When to use me When creating web apps that work offline and can be installed. ## Service Worker ```javascript self.addEventListener('install', e => { e.waitUntil(caches.open('v1').then(c => c.addAll(['/']))); }); self.addEventListener('fetch', e => { e.respondWith(caches.match(e.request).then(r => r || fetch(e.request))); }); ```