Bitcoin Blockchain Explorer: https://bitcoinku.sh/

Using the Mempool API to look up addresses and CoinGecko API to show the current Bitcoin price.

Might also add the current recommended tx fees also from the Mempool API, and of course extra info from the chain for any given address, the Mempool API has some very high quality endpoints available.

This is just a basic starting point for a Bitcoin related React webapp. Again will throw on GitHub once I've refined it a bit and added more functions and data.