7 Zip
Used to open Zipped folders. The best free alternative to WinZip.

Avast
Stay safe from viruses, and malware and secure your passwords. It also has a WiFi security feature to detect and expose intruders in your network.

CamStudio
Allows you to record screen & audio activity on your computer and create video files. Awesome to create tutorials or provide instructions to a client or freelancer.

CCleaner
If your computer starts getting slow, the CCleaner will help speed it up by removing unused files from your pc and freeing up space.

Chrome
Most reliable, faster browser. It allows you to sync on all your devices with your google account.

Color Cop
A multi-purpose color picker – great for web designers and programmers.

Down For Everyone
Is your site down? Use this tool to see if your website is down for other people.

Duplichecker
Quickly check for duplicate content

Writer.com’s plagiarism Checker
Another awesome tool to check for duplicate content. The beauty with this one is that it even offers spell-checking and grammar suggestions all at once.

Evernote
Scan your notes, receipts, etc … it will OCR the content, save it, and make it searchable)

FileZilla
Open-source FTP program for uploading files to your host.

Firefox
Another great alternative web browser.

GIMP
An open-source program used to create & edit – free alternative to Photoshop.

Kompozer
An easy to use WYSIWYG HTML editor.

Open Office
Open-source office software – word processing, spreadsheets, databases, presentations …

Skype
Make free calls over the internet to other people on Skype.

Slack
Slack brings all your communication together in one place. It’s real-time messaging, archiving and search for modern teams.