A Raspberry Pi web app with Flask and Python that lets the user switch 433 MHz outlets on and off from a browser. The project is explained in detail in these blog posts:
https://larsbergqvist.wordpress.com/2016/05/15/rcswitch-revisited-control-rc-outlets-with-a-web-app/
https://larsbergqvist.wordpress.com/2016/11/03/preparing-the-remote-control-app-for-christmas/