Dhikr Counter (PWA)

A free, ad-free dhikr / tasbih counter. One self-contained page (index.html, fonts embedded) plus a manifest and a service worker so it installs and works offline. For https://dhikr-counter-gamma.vercel.app, hosted on Vercel as a plain static site (no build step). The Android app is a Trusted Web Activity wrapper around the same site.

Structure

File	Purpose
index.html	The app (v5) plus SEO tags, JSON-LD, hidden summary, service worker registration
privacy.html	Plain-English privacy page, linked from the info panel
manifest.webmanifest	Install metadata (name, colours, icons)
sw.js	Offline service worker (precache, network-first pages, cache-first assets)
icon-192/512.png, maskable-192/512.png	Manifest icons
apple-touch-icon.png, favicon-32.png, favicon.svg	Browser and iOS icons
icon-play-512.png	Play Store hi-res icon (no transparency)
og-image.png	1200x630 social preview
robots.txt, sitemap.xml	Search engines
vercel.json	Headers: CSP, nosniff, referrer policy, cache and content types
.well-known/assetlinks.json	Digital Asset Links for the Android app (placeholder fingerprint)

Deploy

1. Push this folder to a Git repo and import it in Vercel (Framework: Other, no build command, output directory .), or run vercel --prod inside the folder.
2. Add the domain dhikr-counter-gamma.vercel.app in the Vercel project settings.
3. Replace REPLACE_WITH_PLAY_APP_SIGNING_SHA256 in .well-known/assetlinks.json with the SHA-256 certificate fingerprint from Play Console (App signing).

Updating the app

Any change to a precached file needs two follow-ups:

1. Bump the cache version in sw.js (var CACHE = 'dhikr-v5-1', for example to 'dhikr-v5-2'). Installed copies then fetch the new files and delete the old cache. Visitors online get new pages on their next visit anyway (navigation is network-first), but the version bump refreshes the cached icons and manifest.
2. If you edit either inline <script> in index.html, refresh the CSP hashes in vercel.json. The Content-Security-Policy allows only those two scripts by hash, so an edited script will not run until its hash is updated. Print the new hashes with:

python3 - <<'PY'
import re, hashlib, base64
s = open('index.html').read()
for m in re.finditer(r'<script>(.*?)</script>', s, re.S):
    print("'sha256-" + base64.b64encode(hashlib.sha256(m.group(1).encode()).digest()).decode() + "'")
PY

and paste them into the script-src list. Changes to CSS, text or other files do not need new hashes.

Add any new file that must work offline to the PRECACHE list in sw.js.