WPMU DEV - WPMU offers WordPress Plugins, WordPress Themes, WordPress Multisite and BuddyPress Plugins and Themes.
Hiver - Manage Customer Support, Sales and Projects right from your Gmail inbox. Collaborate with Shared Labels, Shared Contacts, email notes, email reminders and email templates
Firefox Developer Edition - Built for those who build the Web. The only browser made for developers.
MailClark - The Slack bot for external communications
MAMP - MAMP is the abbreviation for Macintosh, Apache, MySQL, and PHP. It is a reliable application with its four components that allows you to access the local PHP server as well as the database server (SQL).
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.