Dashboards

Bitcoin Uptime - Keeping track of bitcoin's near 100% uptime and dependability since its inception.

Bitbo - Popular realtime data dashboard.

Bitcoin Treasuries - BTC holdings in publicly traded and private companies, ETFs and countries.

Clark Moody - The original bitcoin network data dashboard.

TimeChainStats - Customisable fundamental data dashboard.

Explorers

Blockstream.info - Respected block explorer.

The Mempool Open Source Project - Explore the complete bitcoin ecosystem.

Indexes

Timechain Index - Bitcoin holdings by companies, governments, exchanges, ETFs, funds etc.