Reflecting Heroku push version within the app

Every time I push my app to heroku I see the line

-----> Launching... done, v43

Is there a way to make that version number apear within the app so other people can see that number?

Why would you want to depend on running a command after every push? The accepted answer is worse than setting the config yourself.

Instead add to your Gemfile:

gem 'heroku-api'

Add your App name and API key to the Heroku config:

$ heroku config:add HEROKU_APP_NAME=myapp HEROKU_API_KEY=bp6ef3a9...

Then put something like this in config/initializers/heroku.rb:

unless (app_name = ENV["HEROKU_APP_NAME"]).nil?
  require 'heroku-api'

  heroku  = Heroku::API.new(:api_key => ENV["HEROKU_API_KEY"])
  release = heroku.get_releases(app_name).body.last

  ENV["HEROKU_RELEASE_NAME"] = release["name"]
end

Finally:

puts ENV["HEROKU_RELEASE_NAME"]
=> v42

Now it's fully automated. You can forget about it and continue to work on your app.