Jeff Bowers. Professor of Experimental Psychology, University of Bristol
https://jeffbowers.blogs.bristol.ac.uk/blog/

Peter Bowers, Ph.D. WordWorks Literacy Centre
http://www.wordworkskingston.com/WordWorks/Home.html

Matt Berman
www.realspellers.org
Comprehensive; includes links to multiple resources and a video gallery

Douglas Harper
www.etymonline.com dictionary of word origins

Neil Ramsden
Mini Matrix Maker www.neilramsden.co.uk/spelling/matrix/index.html
Word Searcher www.neilramsden.co.uk/spelling/searcher/

Sue Hegland, Learning About Spelling
https://learningaboutspelling.com

Fiona Hamilton, WordTorque
https://wordtorque.com

Lyn Anderson, Beyond the Word
http://wordsinbogor.blogspot.com