Don’t want big brother snooping on your conversation? Try Ring, a secure FOSS alternative to Skype.
Help Open Source projects financially with Gratipay, an open source startup.
If you are looking for a simple calendar application in Linux, try Kalendar. It’s free and open source.
Open Source ebook management software Calibre 3.0 is released with new features and improvements.
Standard Notes is a note taking application that puts particular emphasis on privacy & security. It is cross-platform and of course, completely open-source.