Facebook Sharing Debugger

Facebook Sharing Debugger ensures that you have correctly added markup when website content is shared on Facebook.

Google Search Console

Google Search Console provides tools and reports to help fine-tune websites and increase SEO rankings.

Google Structured Data Testing

Google provides a Structured Data Testing Tool to check that the correct meta data is present within web content.

Let's Encrypt

Let's Encrypt is a free, automated, and open certificate authority which allows you to SSL your site free of charge.
EXCELLENT

mRemoteNG

mRemoteNG is an open source, multi-protocol (including SSH and RDP), remote connections manager.

MxToolbox

MxToolbox provides a large number of free DNS diagnostic tools, allowing testing of domains from a third party.

Notepad++

Notepad++ is a free Notepad replacement with support for tabbed editing and several languages.

Pingdom Website Speed Test

Pingdom provides a reporting tool which allows you to see where your websites are slowing down when loading.

Qualys SSL Server Test

The SSL Server Test from Qualys provides deep analysis and report of the configuration of SSL on web servers.
EXCELLENT

SQLyog for MySQL

SQLyog is a powerful MySQL administration tool, allowing easy management of MySQL databases.

Twitter Card Validator

Twitter Card Validator ensures that you have correctly added markup when website content is shared on Twitter.

Visual Studio Code

Visual Studio Code is a source-code editor with support for debugging, Git control, and syntax highlighting.

web.dev

web.dev provides a concise report and advice to resolve performance and accessibility issues with your websites.