0.00 free dyno hours remaining this month heroku what to do code example

Example: dyno hours meaning

$ heroku ps -a <app name>

650 free dyno hours (65%) used
350 hours remaining

=== web (Free): bundle exec puma -C config/puma.rb (1)
web.1: idle 2016/05/16 15:51:45 -0700 (~ 22h ago)