Healthchecks
A cron monitoring tool written in Python & Django
...When your job does not ping Healthchecks.io on time, Healthchecks.io alerts you! Update your job to send an HTTP request to the ping URL every time the job runs. A list of your checks, one for each Cron job, daemon or scheduled task you want to monitor. Give names and assign tags to your checks to easily recognize them later.