The trick with the free apps are, that you only have one dyno. And after a certain amount of inactivity it will be shut down. Next time somebody tries to reach

The trick with the free apps are, that you only have one dyno. And after a certain amount of inactivity it will be shut down. Next time somebody tries to reach your app, it will automatically be started again. So, the majority of these free apps are practically no-cost for Heroku.