Chain query:

• Link: http://chainquery.com/bitcoin-api/getblockchaininfo
• Description: If you are really into BTC and want to know how the protocol works, you can download Bitcoin Core client and then look things around with Chain query commands
  • Useful commands:
    • getblockchaininfo

    • listunspent

Learnmebitcoin:

• Link: http://learnmeabitcoin.com/browser/node/
• Description: if you want to have a visual representation of what you learn about bitcoin protocol and bitcoin blockchain.

Johoe’s Bitcoin Mempool Statistics:

• Link: https://mempool.observer/#amount-4h
• Description: statistic on number of transactions (Tx) per Satoshi (0.00000001 ฿) per byte