A simple kanban tool holding in one PHP file.
You can rename the file to whatever you want to create multiple boards.
Data will be stored in a .txt file sharing the same name as the .php file. For example, index.php will use a index.txt file, so don't forget to rename the index.txt template too.
Make sure that this file is writable by the webserver, change its owner or:
chmod 777 index.txt