Heroku notes

Some things to consider

• Heroku will destroy your datastore on upgrade, so you must download (click [BACKUP]) and re-upload the url-list.txt from the ZIP file on upgrade, but you will lose the 'history' of snapshots NOTE - (older versions 0.39.5 and older have this bug https://github.com/dgtlmoon/changedetection.io/issues/348 )
• Heroku will pause your instance if you don't use it (you would miss changes then) https://devcenter.heroku.com/articles/free-dyno-hours#dyno-sleeping for this reason. I suggest you use Heroku for staging or testing purposes only, for production releases Heroku is probably a poor choice of platform.
• If you want your Heroku Instance to wake up, you can set up a Scheduler Add-on like Advanced Scheduler. It is not free. Go to Resources - Add-ons - Activate "Advanced Scheduler". You can also find a free Python scripts to wake up the instance if you like.