Bitcoin-only
https://bitcoin-only.com/

Jameson Lopp
https://www.lopp.net/

Bitcoin Resources
https://bitcoin-resources.com/

Lightningnetworkstores
https://lightningnetworkstores.com/

Lightning landscape
https://www.lightning-landscape.net/projects

Stacksats-how
https://www.stacksats.how/

Bolt makers
https://makers.bolt.fun/tournaments/1/projects

Bitcoin Design
https://bitcoin.design/guide/

Bitcoin Rocks
https://bitcoin.rocks/

Bitcointutor
https://www.bitcointutor.net/

Learnmeabitcoin
https://learnmeabitcoin.com/

Armantheparman
https://armantheparman.com/

Bitcoin Blinks
https://en.coinfinity.co/bitcoin-blinks

Woleet
https://www.woleet.io/learn-bitcoin/

What is Bitcoin
https://www.whatisbitcoin.com/

Bitcoindev.network
https://bitcoindev.network/

Bitcoin developer guide
https://developer.bitcoin.org/

Learning Bitcoin from the Commandline
https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line

Chaincode Development Education
https://learning.chaincode.com/