Built with vanilla JavaScript, Firebase, and hosted free on GitHub Pages. No native app required — steps sync automatically from Apple Health or Android Health via a free bridge app.

Features

Passwordless sign-in — magic link sent to email, no password needed
Admin approval — new registrations require administrator approval before access is granted
Auto step sync — bridge apps on iPhone and Android POST steps automatically via webhook
Manual entry — log steps manually if preferred
Friend system — add friends by email, approve or deny requests
Step comparisons — view steps by Today, Week, Month, Year, or All Time
Profiles — display name and avatar URL per user
Mobile-first — designed for use in a mobile browser, works as a PWA

How It Works

iPhone/Android Health App
        ↓
  Bridge App (free)
        ↓
  Webhook URL (Firebase Cloud Function)
        ↓
  Firestore Database
        ↓
  Step Tracker Web App (GitHub Pages)

Tech Stack

Layer	Technology	Cost
Frontend	Vanilla JS, HTML, CSS	Free
Hosting	GitHub Pages	Free
Auth	Firebase Authentication (magic link)	Free
Database	Firebase Firestore	Free tier
Backend	Firebase Cloud Functions	Free tier

Setup Your Own Instance

Prerequisites

A Firebase account
A GitHub account
Node.js installed (LTS version)

1. Create a Firebase Project

Go to console.firebase.google.com
Click Add project → name it → disable Analytics → Create project

2. Enable Passwordless Email Auth

Firebase Console → Authentication → Get started
Click Email/Password → enable Email link (passwordless sign-in) → Save
Settings → Authorized domains → add yourusername.github.io

3. Create Firestore Database

Firebase Console → Firestore Database → Create database
Choose Start in test mode → pick a region → Done
Click the Rules tab and paste:

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /users/{userId} {
      allow read, write: if request.auth != null && request.auth.uid == userId;
    }
    match /profiles/{userId} {
      allow read: if request.auth != null;
      allow write: if request.auth != null && request.auth.uid == userId;
    }
    match /friendRequests/{reqId} {
      allow read: if request.auth != null &&
        (resource.data.fromUid == request.auth.uid ||
         resource.data.toUid == request.auth.uid);
      allow create: if request.auth != null &&
        request.resource.data.fromUid == request.auth.uid;
      allow update: if request.auth != null &&
        resource.data.toUid == request.auth.uid;
    }
  }
}

Click Publish.

4. Deploy Cloud Functions

npm install -g firebase-tools
firebase login
mkdir step-tracker-fn && cd step-tracker-fn
firebase init functions
# Choose: JavaScript, No ESLint, Yes to install dependencies

Copy the contents of functions/index.js from this repo into your functions/index.js.

Install nodemailer:

cd functions && npm install nodemailer

Set your secrets (Firebase will prompt for each value):

firebase functions:secrets:set ADMIN_EMAIL
firebase functions:secrets:set ADMIN_SECRET
firebase functions:secrets:set APP_URL
firebase functions:secrets:set GMAIL_USER
firebase functions:secrets:set GMAIL_PASS

GMAIL_PASS must be a Gmail App Password, not your regular password. Generate one at myaccount.google.com/apppasswords

Deploy:

cd .. && firebase deploy --only functions

Copy the function URLs shown after deployment.

5. Configure the App

Copy config.example.js to config.js and fill in your values:

window.STEPMATES_CONFIG = {
  firebase: {
    apiKey: "YOUR_API_KEY",
    authDomain: "YOUR_PROJECT.firebaseapp.com",
    projectId: "YOUR_PROJECT_ID",
    storageBucket: "YOUR_PROJECT.firebasestorage.app",
    messagingSenderId: "YOUR_SENDER_ID",
    appId: "YOUR_APP_ID"
  },
  webhookBase: "https://YOUR_WEBHOOK_URL.a.run.app",
  adminNotifyUrl: "https://us-central1-YOUR_PROJECT.cloudfunctions.net/adminNotify",
  adminSecret: "YOUR_ADMIN_SECRET",
  appUrl: "https://yourusername.github.io/step-tracker"
};

Get your Firebase config from: Firebase Console → gear icon → Project Settings → Your Apps → Add app → Web.

6. Publish to GitHub Pages

Create a GitHub repo named step-tracker
Rename stepmates.html → index.html
Upload index.html, config.js, and .gitignore
Go to repo Settings → Pages → Deploy from branch → main / root → Save
Your app will be live at https://yourusername.github.io/step-tracker

Bridge App Setup

Share these instructions with your friends after they register.

iPhone — Health Auto Export

Download: App Store
Automations → New Automation → Webhook → paste your personal webhook URL
Data types: Step Count
Schedule: Daily

Android — HC Webhook

Download: GitHub Releases (free, open source)
Add Webhook → paste your personal webhook URL
Enable Steps → set sync interval

Each user gets their own unique webhook URL shown in the app after sign-in.

Admin Approval Flow

New user enters email → receives magic sign-in link
After clicking the link, their account is created with approved: false
Administrator receives an email with Approve and Deny buttons
User sees a "Waiting for approval" screen until approved
Once approved, they proceed to onboarding

Free Tier Limits

Service	Free Allowance	Expected Usage
Firebase Auth	Unlimited	Fine
Firestore reads	50,000/day	Fine for small groups
Firestore writes	20,000/day	Fine
Cloud Functions	2M calls/month	Fine (a few calls/day)
GitHub Pages	Unlimited	Fine

Expected monthly cost: $0

Roadmap

Step contests with start/end dates
Weekly recap emails
Streak tracking
Push notifications when a friend passes you
Leaderboard with rank change indicators

License

MIT — do whatever you want with it.