At the moment, it's free. I've got a number of apps running, and I've got nothing but praise for Heroku. From what I remember, their plan was to bill based on

At the moment, it's free. I've got a number of apps running, and I've got nothing but praise for Heroku. From what I remember, their plan was to bill based on usage, so if you have a quiet month, you get a small(ish) bill. Things get busy; you pay more.