Founder of Zube here. GitHub Projects seems like a nice solution for very small teams, side projects and open source projects. However, serious teams need more

Founder of Zube here. GitHub Projects seems like a nice solution for very small teams, side projects and open source projects. However, serious teams need more powerful features like a well thought out workflow, support for multiple repos and burndown charts. Shameless plug: Zube has all these things and more - https://zube.io https://zube.io :)