ITEAD's SONOFFs are Wi-Fi enabled relays that can be used to turn applicances on and off remotely. The firmware they come with did not suit my needs so I wrote and flashed my own. This can be achieved easily since the SONOFFS are built around an ESP8266 chip, which can be programmed with the Arduino IDE.
Here is a list of functions that the custom firmware features:
- MQTT support with JSON payloads
- REST API
- Control through web interface
- Update through web interface
- Update using Arduino OTA
Source code available on GitHub.