Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Tiny Flashlight + LED - Tiny Flashlight + LED is free to use application that can be used anywhere else, having nicely built-in functionality.
ioBroker - flexible and modular application for the IoT and Smarthome
Hmu - Hmu is a social app by SC Friends that enables users to search for new friends by viewing a list of users from all around the globe and tap on the desired profile to engage in live chat with them.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Flashlight - Control your Mac with a keystroke.