I built a free blockchain intelligence tool at kettaro.com and just shipped Bitcoin whale tracking. It scans recent blocks via the Mempool.space API, pulls transactions above a configurable BTC threshold (1–500+ BTC), and displays them in real-time with auto-refresh. You get sender/receiver addresses, BTC amounts, USD values, and block confirmations — no account required. The BTC tracker sits alongside Kettaro's existing EVM tools: wallet profiling across 10 chains (Ethereum, Base, Polygon, Arbitrum, Optimism, Avalanche, etc.), transaction tracing with visual graphs, NFT provenance verification, and a smart money tracker that monitors 50+ known whale wallets. Stack: Python/Flask backend on Render, React frontend, PostgreSQL, Mempool.space API for Bitcoin, Etherscan API v2 for EVM chains. Try it: kettaro.com/btc/whale-activity Would love feedback — especially on what other Bitcoin analytics would be useful.