Corvée Ninja is a website I am in the process of developing to make my own life a bit easier (and, perhaps the lives of others if it ever works).
The main idea is that the website will allow you to schedule recurring tasks for a group to complete and get reminders when they are overdue.
The main difference from a calendar event is that the recurrence rules will be based on a task needing to be completed every N days from when it was last completed, not every Nth day from when it was first completed.
The website is being built using python3.6 and a custom ASGI framework owlbear running under uvicorn. The application instances are being run in docker containers on a managed Kubernetes cluster in Google Cloud, using a managed PostgreSQL database as the primary data storage layer.