[ksylvest]

You can keep a single free Dyno "awake" by hitting it with a request at least once per hour. If you use New Relic the built in availability monitoring will do the trick and otherwise Scheduler should work. For more info:

https://devcenter.heroku.com/articles/dynos#dyno-idling

[felipesabino]

Now you can also check if your app is sleeping on the dashboard :)

https://blog.heroku.com/archives/2013/6/20/app_sleeping_on_h...

Also, I used pingdom.com once to make sure that my "very low in traffic" app never sleeps, but any solution that performs a request in this interval would be valid