Are there other free sites like Heroku? I want to deploy on other
sites as well, so that I caern see what the differences are from one
site to another.
I can also suggest Cloud 66 (www.cloud66.com) which is an application
management as a service. It configures, deploys and manages your web
applications and mobile backends on any cloud or your own servers
without the need to for any download or sysop.
Another alternative worth looking at is Shelly Cloud:
https://shellycloud.com Deployment is done via git like in Heroku, but
it differs in that you get whole virtual servers that you can utilize in
different ways: for application servers, delayed_job workers, databases,
etc. It comes with free credit, so you can play with it for about a
month (depending on usage) without paying anything.