Cronitor - Monitor cron jobs, micro-services, daemons and almost anything else, no setup required. Easier cron troubleshooting and no more silent failures.

crontab guru - The quick and simple editor for cron schedule expressions by Cronitor

Trello Calendar Connector by Cronofy - See and Organize your Trello deadlines inside your calendar

Agile Guy for Trello - The Swiss army knife for agile teams!

FastCron - Online cron job service

Freelance.watch - As a freelancer or agency, juggling existing projects while finding new ones is always a headache.