Nowadays, it is important to find an optimal way to work with your teammates. Luckily, there are quite a few tools out there, which help with this.
After a quick search on github.com, the following projects came to my attention:
Some “big dogs”:
Rather free online tools:
An awkward choice would be Taskwarrior, which is mainly used in command line:
An interesting and simple comparison between kanban and scrum:
And a related github repository, for invoicing application: