majiayu000 Browser App Creator
Purpose
Creates production-ready single-file web applications that work offline with zero setup. Perfect for quick tools, dashboards, trackers, and prototypes.
For ADHD users: Large buttons (60px+), auto-save everything, visual feedback, zero configuration. For SDAM users: All data persists in localStorage with timestamps. For all users: Download and use immediately - no server, no build step, no dependencies.
Activation Triggers
- User says: "create app", "build tool", "make dashboard", "create tracker"
- Requests for: habit tracker, todo list, timer, calculator, form, visualization
- Any request for a browser-based interface or tool
Core Workflow
1. Understand Requirements
Ask clarifying questions only if absolutely necessary:
{
app_type: "dashboard|tracker|form|tool|visualization",
primary_function: "What does the app do?",
data_to_track: ["What data needs to be stored?"],
key_actions: ["What can users do?"],
visual_requirements: "Any specific layout needs?"
}
2. Generate Single-File App
Template structure:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>{App Name}</title>
<style>
/* ADHD-Optimized Styles */
</style>
</head>
<body>
<!-- App UI -->
<script>
// App Logic + localStorage
</script>
</body>
</html>
3. ADHD Optimization Requirements
Required UI elements:
- ✅ Buttons: Minimum 60px height, high contrast
- ✅ Dark mode: Default theme (can toggle)
- ✅ Auto-save: Every action saves to localStorage
- ✅ Visual feedback: Success/error messages
- ✅ Mobile responsive: Works on all screen sizes
- ✅ Large touch targets: 44px minimum for mobile
CSS Requirements:
/* ADHD-Optimized Base Styles */
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
background: #1a1a1a;
color: #e0e0e0;
padding: 20px;
max-width: 1200px;
margin: 0 auto;
}
button {
min-height: 60px;
padding: 15px 30px;
font-size: 18px;
font-weight: 600;
border: none;
border-radius: 8px;
cursor: pointer;
transition: all 0.2s ease;
background: #4a9eff;
color: white;
}
button:hover {
background: #357abd;
transform: translateY(-2px);
box-shadow: 0 4px 12px rgba(74, 158, 255, 0.4);
}
button:active {
transform: translateY(0);
}
input, textarea, select {
min-height: 50px;
padding: 12px 15px;
font-size: 16px;
border: 2px solid #333;
border-radius: 6px;
background: #2a2a2a;
color: #e0e0e0;
width: 100%;
}
input:focus, textarea:focus, select:focus {
outline: none;
border-color: #4a9eff;
box-shadow: 0 0 0 3px rgba(74, 158, 255, 0.2);
}
4. localStorage Pattern
Always include:
// localStorage Manager
const Storage = {
key: 'app-name-data',
save(data) {
try {
localStorage.setItem(this.key, JSON.stringify({
...data,
lastUpdated: new Date().toISOString()
}));
this.showFeedback('✅ Saved!');
} catch (error) {
this.showFeedback('❌ Save failed', true);
console.error('Save error:', error);
}
},
load() {
try {
const data = localStorage.getItem(this.key);
return data ? JSON.parse(data) : this.getDefaults();
} catch (error) {
console.error('Load error:', error);
return this.getDefaults();
}
},
getDefaults() {
return {
items: [],
settings: {},
created: new Date().toISOString()
};
},
showFeedback(message, isError = false) {
const feedback = document.createElement('div');
feedback.textContent = message;
feedback.style.cssText = `
position: fixed;
top: 20px;
right: 20px;
padding: 15px 25px;
background: ${isError ? '#ff4444' : '#44ff88'};
color: #000;
border-radius: 8px;
font-weight: 600;
box-shadow: 0 4px 12px rgba(0,0,0,0.3);
z-index: 1000;
animation: slideIn 0.3s ease;
`;
document.body.appendChild(feedback);
setTimeout(() => feedback.remove(), 2000);
}
};
// Auto-save on any change
function autoSave(data) {
Storage.save(data);
}
// Load on page load
let appData = Storage.load();
5. App Templates
See templates.md for complete examples of:
- Dashboard: Metrics, charts, status indicators
- Tracker: Habits, tasks, progress
- Form: Data entry, validation, submission
- Tool: Calculators, converters, utilities
- Visualization: Charts, graphs, timelines
6. Deliver the App
Format:
✅ **{App Name}** complete!
**Features**:
- {Feature 1}
- {Feature 2}
- {Feature 3}
**Usage**:
1. Save the file as `{app-name}.html`
2. Open in any browser
3. Works offline
4. Data auto-saves to your browser
**Customization**:
- Colors: Edit the CSS variables at the top
- Features: Modify the JavaScript section
- Layout: Adjust the HTML structure
Then provide the complete HTML file.
Common App Types
Dashboard
Purpose: Display metrics, status, and key information Elements: Cards, charts, progress bars, status indicators Data: Real-time or static metrics Example: Project status dashboard, analytics viewer
Tracker
Purpose: Record and monitor recurring items Elements: Add/remove items, checkboxes, timestamps Data: List of items with status and dates Example: Habit tracker, task list, mood journal
Form/Input
Purpose: Collect and validate user input Elements: Input fields, validation, submit button Data: Form submissions with timestamps Example: Survey, calculator, data entry tool
Visualization
Purpose: Display data visually Elements: Charts, graphs, timelines Data: Visual representation of datasets Example: Chart builder, timeline viewer, graph tool
Interactive Tool
Purpose: Perform specific tasks or calculations Elements: Controls, real-time updates, results Data: Temporary or persistent tool state Example: Timer, converter, game, simulator
Advanced Features
Dark/Light Mode Toggle
function toggleTheme() {
const currentTheme = document.body.dataset.theme || 'dark';
const newTheme = currentTheme === 'dark' ? 'light' : 'dark';
document.body.dataset.theme = newTheme;
localStorage.setItem('theme-preference', newTheme);
}
// Load saved theme
document.body.dataset.theme = localStorage.getItem('theme-preference') || 'dark';
Export Data
function exportData() {
const data = Storage.load();
const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' });
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = `app-data-${Date.now()}.json`;
a.click();
URL.revokeObjectURL(url);
}
Import Data
function importData() {
const input = document.createElement('input');
input.type = 'file';
input.accept = 'application/json';
input.onchange = (e) => {
const file = e.target.files[0];
const reader = new FileReader();
reader.onload = (event) => {
try {
const data = JSON.parse(event.target.result);
Storage.save(data);
location.reload();
} catch (error) {
alert('Invalid file format');
}
};
reader.readAsText(file);
};
input.click();
}
Browser Notifications
async function notifyUser(title, body) {
if ('Notification' in window && Notification.permission === 'granted') {
new Notification(title, { body });
} else if (Notification.permission !== 'denied') {
const permission = await Notification.requestPermission();
if (permission === 'granted') {
new Notification(title, { body });
}
}
}
Styling Guidelines
See styling.md for:
- Complete CSS framework
- Color schemes
- Responsive breakpoints
- Animation patterns
- Accessibility guidelines
Integration with Other Skills
Rapid Prototyper
If app needs backend:
browser-app-creator → Creates frontend
rapid-prototyper → Creates backend API
Result: Full-stack app
Context Manager
Save app decisions:
remember: Created habit tracker with localStorage
Type: PROCEDURE
Tags: browser-app, localStorage, tracking
Error Debugger
If app has bugs:
Automatically invokes error-debugger for:
- JavaScript errors
- localStorage issues
- Browser compatibility
Quality Checklist
Before delivering, verify:
- ✅ Single file (HTML + CSS + JS)
- ✅ Works offline (no external dependencies)
- ✅ Buttons ≥60px height
- ✅ Dark mode default
- ✅ localStorage auto-save
- ✅ Visual feedback on actions
- ✅ Mobile responsive
- ✅ No console errors
- ✅ Data persists on reload
Example Output
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Habit Tracker</title>
<style>
/* Complete styles here */
</style>
</head>
<body>
<h1>Habit Tracker</h1>
<div id="app">
<!-- App UI here -->
</div>
<script>
// Complete logic here
</script>
</body>
</html>
Success Criteria
✅ App works immediately after opening ✅ Data persists across browser sessions ✅ ADHD-optimized (large buttons, auto-save) ✅ No setup or installation required ✅ Mobile-friendly ✅ Professional appearance ✅ Intuitive to use ✅ Handles errors gracefully
Additional Resources
- App Templates - Complete working examples
- Styling Guide - CSS patterns and color schemes
Quick Reference
Trigger Phrases
- "create app"
- "build tool"
- "make dashboard"
- "create tracker"
- "build calculator"
- "make timer"
File Location
All created apps should be saved to:
- Linux/macOS:
~/.claude-artifacts/ - Windows:
%USERPROFILE%\.claude-artifacts\
Common Patterns
| App Type | Key Feature | localStorage Structure |
|---|---|---|
| Tracker | List + checkboxes | { items: [...], dates: {...} } |
| Dashboard | Cards + metrics | { metrics: {...}, updated: "" } |
| Form | Input + validation | { submissions: [...] } |
| Tool | Controls + results | { settings: {...}, history: [...] } |