Houseparty - Brining empathy to online communication.
Okular - Okular is a universal document viewer based developed by KDE.
Booyah - Video chat with up to 12 friends at the same time.
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
Slack - A messaging app for teams who see through the Earth!
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.