Here is an open-source version I made called TaskGraph [1], a fork from uber/react-digraph[2]. I made it for my startup [3] because I didn't really like Jira in the context of 3 people.
We have been using it for a couple of months and it works really well. Apologies in advance for the lack of documentation. If you have any questions by all means.
TaskGraph has:
- Task status (todo/in-progress/done)
- Task completion estimation (admittedly it assumes you can work perfectly in parallel which is a bit of a stretch.)
[1] https://github.com/openquery-io/taskgraph/