Some of my favourite things, in no particular order

Web Security

• 6G Blacklist (Beta): https://perishablepress.com/6g-beta/

Historical DNS Data

• https://securitytrails.com/

WordPress Plugins

• SMTP mail: https://en-gb.wordpress.org/plugins/easy-wp-smtp/
• Search & Filter: https://searchandfilter.com/

Developer Tools

• https://www.adminer.org/

Password Generator

• http://www.dinopass.com/

Web Fonts

• https://fortawesome.github.io/Font-Awesome/

Source Code Managment

• https://bitbucket.org/

Deploying Websites

• https://github.com/capistrano/capistrano
• https://github.com/capistrano/sshkit

Free WordPress Themes

• https://github.com/somerandomdude/Frank

API Services

• PHP SMS messaging: https://github.com/twilio/twilio-php

Linux Software

• Desktop client for Slack: https://github.com/raelgc/scudcloud

CakePHP 3 ACL

• Official Plugin: https://github.com/cakephp/acl
• Tutorial: https://github.com/mattmemmesheimer/cakephp-3-acl-example

Image Editing

• Remove Backgrounds from Images: https://www.remove.bg/