Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
ioBroker - flexible and modular application for the IoT and Smarthome
Slack - A messaging app for teams who see through the Earth!
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation