Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
DejaGnu - DejaGnu is a framework for testing other programs.
Timber - Open source material design music player
Expect - Expect is a tool for automating interactive applications such as telnet, ftp, passwd, fsck, rlogin...
Todo for hackers - CLI Todo app for hackers
Check - Check is a unit testing framework for C, which runs on environments such as GNU/Linux, GNU/Hurd, BSD, and Mac OSX.