Subdomain Session Not Working in Rails 2.3 and Rails 3 on Heroku with/without a Custom Domain?

Question

So I have two heroku apps:

• http://production-app.com (mapped from http://production-app.heroku.com)
• http://development-app.heroku.com

O

Answer 1

On development-app.heroku.com, I also have those custom subdomains, but since I don't have a custom domain, I just use the wildcard addon.

Is this addon still available for using custom subdomains like api.mydevdomain.herokuapp.com ?