SudoLikeABoss (Free) - Plugin to iTerm, fill passwords on your terminal with a keyboard shortcut.
Cathode ($7.99) - Another awesome terminal emulator
Shell
zsh (Free) - Powerful shell that operates as both an interactive shell and as a scripting language interpreter
oh-my-zsh (Free) - Oh-My-Zsh is an open source, community-driven framework for managing your ZSH configuration. It comes bundled with a ton of helpful functions, helpers, plugins and themes.
fish (Free) - Smart and user-friendly command line shell for OS X, Linux, and the rest of the family.
Postgres App (Free) - The easiest way to get started with PostgreSQL on the Mac, this way you can start/stop Postgres at the Mac OS X menubar. It comes with batteries included.
Sequel Pro (Free) - MySQL management GUI specific for Mac OS X.
Sqlite Browser (Free) - Sqlite management GUI with binaries included for Mac OS X.
RoboMongo (Free) - MongoDB management GUI mixed with the full power of the shell commands. Includes binaries for Mac OS X.
Virtualization
Kitematic (Free) - The easiest way to use Docker on Mac.
Design
Prepo (Freemium) - No more pain creating all necessary sizes of icons when developing a App for Android an iOS.
Sketch ($99) - The best software to design user interfaces and with a great community developing plugins and tutorials.
Pixelmator for Mac ($29.99) - Full-featured image editing app for the Mac and much more cheap than Adobe solution.
Teams
Communication
Campfire - Simple web-based real-time group chat tool for business. It makes real-time communication with 2-60 people as simple as visiting a web page.
HipChat - Hosted group chat and video chat built for teams. Supercharge real-time collaboration with persistent chat rooms, file sharing, and screen sharing.
Sococo - Remote team communication software, support video/audio and screen-sharing
Slack - Team communication software with several integrations for development tools, such as github, gitlab, jenkins, ...