Coinflow

A polished Android home-screen widget and companion app for live multi-coin crypto price tracking.

Features

• Live prices for any number of coins, pulled from Kraken's public market API (no key required)
• Sparkline charts showing 24-hour price history with green/red glow segments
• Multi-coin widget — pick up to 5 coins, swipe between them on a single 4×2 widget
• Wallet balance tracking — XRPL, Bitcoin, Ethereum, Solana, plus generic REST endpoints for custom coins
• Multi-coin portfolio screen — total value, 24h delta, per-coin allocation breakdown
• Configurable refresh intervals — 15m, 30m, 1h, 2h, 6h
• Price alerts — ABOVE/BELOW thresholds in crossing, repeating, or one-shot modes
• Themeable — Cyber, Amber, Matrix, Midnight, or fully custom accent + secondary
• BYOC (Bring Your Own Coin) — add any Kraken pair, or wire up a custom REST endpoint with dot-notation JSON paths

Architecture

CoinflowApplication (Hilt)
  └── WorkScheduler
        └── PriceUpdateWorker (WorkManager, periodic)
              ├── CryptoRepository
              │     ├── KrakenService   (price + OHLC sparkline, any pair)
              │     ├── XrplService     (XRPL wallet balance)
              │     ├── BitcoinService  (Blockstream.info balance)
              │     ├── EthereumService (eth.llamarpc.com JSON-RPC balance)
              │     ├── SolanaService   (mainnet-beta JSON-RPC balance)
              │     └── GenericRestService (custom URL + JSON path for BYOC)
              ├── CoinRepository (built-in + Room-stored custom coins)
              ├── WidgetUpdater → RemoteViews → CoinflowWidgetProvider
              ├── AlertRepository → checkAndFireAlerts
              └── AlertNotifier → NotificationManager

Built-in coins

Symbol	Name	Kraken pair	Wallet support
BTC	Bitcoin	XBTUSD	Blockstream.info
ETH	Ethereum	ETHUSD	eth.llamarpc.com
SOL	Solana	SOLUSD	mainnet-beta JSON-RPC
XRP	XRP	XRPUSD	xrplcluster.com

Add more via the in-app Add Coin flow — either pick from the full Kraken pair list or supply a custom REST endpoint.

Build

# Debug build
./gradlew assembleDebug

# Release build (minified + shrunk)
./gradlew assembleRelease

Requires:

• JDK 17+
• Android SDK with API 35 build tools
• Android device/emulator with API 26+ (Android 8.0)

Install

./gradlew installDebug

Setup

1. Open the Coinflow app and tap the coins you want to follow.
2. Pick which followed coins appear as widget tabs (max 5).
3. Add the widget to your home screen (long-press → Widgets → Coinflow).
4. Optional: tap a coin on the home tracker to set a wallet address or configure price alerts.

Min SDK

API 26 (Android 8.0 Oreo).