You will need to configure apache to serve a virtual domain for tweakercat.tk
Currently apache only knows about the default domain, you will need to create a config file in /etc/apache2/sites-available and symlink it to /etc/apache2/sites-enabled
The file will need the following contents (at least)...
CustomLog /var/log/apache2/tweakercat.tk-access.log combined
I would also recommend putting this site somewhere else than a directory called 'php'
I generally create a directory structure something like...
/var/www/default/ (default site)
and have the appropriate files in /etc/apache2/sites-available