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

Google Calendar - Spend less time managing your day & more time enjoying it

Bringschuld - Simple periodic task and email monitoring

Jorte - Schedule books must be practical and has a good design.

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

Business Calendar - Powerful and easy to use calendar app for Android including weather, widgets and tasks.