A barebones PHP app that makes use of the Silex web framework, which can easily be deployed to Heroku.
This application supports the Getting Started with PHP on Heroku article - check it out.
Install the Heroku Toolbelt.
$ git clone git@github.com:heroku/php-getting-started.git # or clone your own fork
$ cd php-getting-started
$ heroku create
$ git push heroku master
$ heroku open
For more information about using PHP on Heroku, see these Dev Center articles: