ioBroker - flexible and modular application for the IoT and Smarthome
ThingSpeak - Open source data platform for the Internet of Things. ThingSpeak Features
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
The IoT Guru - the IoT cloud backend company
Google Home - Set up, manage, and control your Chromecast, Chromecast Audio and Google Home devices.
dweet.io - Ridiculously simple data sharing for the Internet of Things.