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

Loxi - Easily add an events calendar to any website.

Bringschuld - Simple periodic task and email monitoring

Future - Calendar events around the clock

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

Whenever - Casual calendar app for iOS