[mdtrooper]

Some years ago, I used Kanboard (it written in php): https://kanboard.org/ . It was ugly but useful (and easy to install because I remember that it didn't need any data base).

[rsolva]

I threw it on a shared host and was up and running in notime. The UI is dated, but it is very functional.

[kiney]

I still use it. Love the simplicity.