The application is written in pure PHP. Fuck frameworks! Pure PHP only!

Clone git-repository, change directory to project root and run composer install.

git clone git@github.com:memclutter/php-todo.git 
cd php-todo
composer install

Create PDO-compatibility database and create local config file, placed in config.local.php

<?php

return [
    'pdo' => [
        'dsn' => 'mysql:dbname=todo;host=localhost;charset=utf8',
        'username' => 'todo',
        'passwd' => 'secret',
    ],
];

Run local webserver.

php -t www -S localhost:8080
# or
composer runserver

See http://localhost:8080.