Tuya Smart - Tuya Smart is a free to use Lifestyle Application by Tuya Inc.
FHEM - FHEM (TM) is a GPL'd perl server for house automation.
EseeCloud - EseeCloud is a powerful mobile video surveillance app that lets you keep an eye on your property from anywhere in the world.
Homebridge.io - Homebridge is a lightweight NodeJS server you can run on your network that emulates the iOS HomeKit...
Kasa for Mobile - Kasa for Mobile is a mobile app that lets you add, configure, monitor, and control all your TP-LINK Smart Home devices from anywhere around the world.
Conrad Connect - Service for managing smart home devices