Every API below works in a FreeAppStore app. Combine them with the platform capabilities (auth, storage, real-time, AI proxy) and you can build things that compete with native apps.
Media & Input
Camera & Microphone
navigator.mediaDevices.getUserMedia(). Access front/rear camera, microphone. Live video/audio streams.
Video recorder, voice memo app, photo booth, QR scanner, video chat.
Screen Recording
navigator.mediaDevices.getDisplayMedia(). Capture screen, window, or tab as a video stream.
Screen recorder, tutorial maker, bug reporter with video evidence.
Web Audio API
Low-level audio processing. Oscillators, filters, gain nodes, analyzers, spatial audio. Real-time synthesis and effects.
Synthesizer, guitar tuner, drum machine, audio visualizer, white noise generator, metronome.
Speech Recognition
SpeechRecognition. Real-time speech-to-text in 100+ languages. Continuous or one-shot.
Voice notes, dictation app, language learning, voice-controlled interface, accessibility tool.
Speech Synthesis
speechSynthesis.speak(). Text-to-speech with multiple voices, pitch, rate control.
Reading assistant, pronunciation trainer, screen reader, audiobook creator.
Gamepad API
navigator.getGamepads(). Read Xbox, PlayStation, and generic USB/Bluetooth controllers.
Controller tester, game input mapper, accessibility controller, MIDI-style input.
Sensors & Location
Geolocation
navigator.geolocation.getCurrentPosition(). GPS coordinates, altitude, speed, heading. One-shot or watch.
Run tracker, delivery tracker, weather by location, nearby places finder, geo-tagged photo journal.
Device Orientation
DeviceOrientationEvent. Gyroscope + accelerometer. Alpha (compass), beta (tilt), gamma (rotation).
Spirit level, compass, tilt-controlled interface, motion-based game controller, panorama viewer.
Ambient Light Sensor
AmbientLightSensor. Reads ambient light level in lux. Auto-theme switching, display adaptation.
Auto dark mode, light meter for photography, reading comfort optimizer.
Vibration
navigator.vibrate(). Haptic feedback with custom patterns. Duration in milliseconds.
Timer with haptic alert, Morse code teacher, accessible notification, game feedback.
Storage & Files
IndexedDB
Client-side structured database. Stores megabytes of data. Transactional, indexed queries. Survives page reload.
Offline-first note app, local-first spreadsheet, cached API data, draft manager.
File System Access
showOpenFilePicker(), showSaveFilePicker(). Read/write real files on the user's disk. Directory access too.
Code editor, image editor with save, CSV processor, local backup tool.
Clipboard
navigator.clipboard.readText() / .writeText(). Also supports images and rich content.
Clipboard manager, password generator, code snippet tool, image converter.
Cache API + Service Worker
Full offline support. Cache assets, API responses, pages. Background sync when connection returns.
Offline-first todo, reading app that works on planes, field data collector.
Share API
navigator.share(). Native share sheet on mobile. Share text, URLs, files to any installed app.
Share button for any content, social posting tool, receipt sharer.
Graphics & Rendering
Canvas 2D
<canvas>. Pixel-level drawing. Shapes, text, images, transforms. Up to 60fps animation.
Drawing app, chart renderer, image editor, signature pad, pixel art tool, whiteboard.
WebGL / WebGL2
GPU-accelerated 3D rendering. Shaders, textures, lighting. Powers Three.js, Babylon.js, PlayCanvas.
3D viewer, product configurator, data visualization, architectural walkthrough.
WebGPU
Next-gen GPU API. Compute shaders, modern rendering pipeline. 3-10x faster than WebGL for complex scenes.
ML inference in browser, physics simulation, ray tracing, advanced data viz.
CSS Animations + WAAPI
Web Animations API. Hardware-accelerated. Keyframes, easing, composition. Performant on mobile.
Animated onboarding, micro-interactions, scroll-driven animations, loading states.
Communication & Connectivity
WebSocket
Full-duplex real-time communication. The FreeAppStore SDK wraps this as fas.rooms.
Chat app, live dashboard, collaborative editor, real-time notifications.
WebRTC
Peer-to-peer video/audio/data. No server needed for the media stream (signaling server still required).
Video call app, peer-to-peer file sharing, screen sharing tool, remote pair programming.
Web Bluetooth
navigator.bluetooth.requestDevice(). Connect to BLE devices. Read/write characteristics.
Heart rate monitor, smart light controller, IoT dashboard, fitness tracker companion.
Web USB
navigator.usb.requestDevice(). Direct communication with USB devices from the browser.
Arduino programmer, firmware flasher, USB device tester, hardware debugger.
Push Notifications
PushManager.subscribe(). Receive notifications even when the app isn't open. Requires service worker.
Reminder app, price alert, chat notification, daily habit nudge.
PWA & System Integration
Install to Home Screen
PWA manifest + service worker = installable app. Full-screen, no browser chrome, app icon on home screen.
Every FreeAppStore app is already a PWA. Users can install it like a native app.
Badging API
navigator.setAppBadge(count). Show unread count on the app icon. Works when installed as PWA.
Unread messages count, pending tasks badge, notification counter.
Web Workers
Background threads. CPU-intensive work without blocking the UI. Blob-URL workers are allowed on FreeAppStore hosting. SharedArrayBuffer and threaded wasm need cross-origin isolation: set "crossOriginIsolated": true in fas.json and run fas publish. Off by default — COOP/COEP break third-party embeds and window.opener. Guide: capabilities.
Image processing, data crunching, markdown rendering, syntax highlighting, spell checking.
WebAssembly
Run C/C++/Rust/Go at near-native speed in the browser. SQLite, FFmpeg, OpenCV, TensorFlow all have WASM builds.
Local SQLite database, image/video processing, PDF renderer, code compiler, CAD tool.
AI in the browser
WebNN (Neural Network API)
Hardware-accelerated ML inference. Runs models on GPU/NPU without a server.
On-device image classification, text analysis, real-time object detection without API costs.
TensorFlow.js / ONNX Runtime
Run ML models in the browser via WebGL/WebGPU/WASM. Pre-trained models for vision, NLP, pose detection.
Background removal, face filter, handwriting recognition, sentiment analysis, music generation.
Platform AI Proxy
Combine browser APIs with server-side AI via fas.proxy.fetch(). User's own OpenAI/Anthropic/Google AI key.
AI writing assistant, code generator, image describer, chatbot, translation tool, summarizer.