I’m building a virtual stock-trading experience focused on the Indian markets and need a seasoned Android developer who can deliver a smooth, market-accurate simulator tied to both NSE and BSE feeds. The app should feel as close to a real brokerage account as possible while remaining 100 % risk-free for users. Core scope • Connect to live NSE & BSE data streams (Level-1 quotes are fine; faster WebSocket delivery preferred). • Display real-time price updates across watchlists, charts and order tickets with minimal latency. • Let users create and rebalance a virtual portfolio, track P&L, and inspect trade history. • Support market, limit and stop orders in a sandbox environment—orders must execute instantly at current market price to mimic live fills. • Gate full functionality with a single, one-time payment; integrate Google Play Billing to handle that purchase and gracefully manage entitlements. Tech expectations Android Studio with Kotlin is ideal, though Java is acceptable. I’m comfortable with common charting libraries (MPAndroidChart, TradingView widget) and standard back-end stacks (Firebase, Node, or any RESTful service) as long as you detail how data is cached and refreshed. Acceptance check 1. I can install an APK, toggle a setting to point at live or mock data, and see quotes match NSE/BSE ticker pages within a two-second window. 2. A test account can place five distinct orders and view accurate positions/PNL after each fill. 3. After purchasing the one-time unlock in Google Play’s sandbox, all premium screens stay available on every subsequent launch. Hand-off items • Full Android source, buildable in the latest stable Android Studio. • API keys, documentation and any back-end code needed to reproduce the live feed. • A brief README outlining setup, data architecture, and extension points. If you have past work with market data APIs or gamified finance apps, send a quick note and link—looking forward to collaborating.