We have electric 3 mattress heaters at home. Each is turned on/off by a momentary push button. It takes ~30 min to warm up and we always forget to turn them on in time. Timed electrical outlet doesn’t work, only pushing the button turns a heater on or off.
I came up with the following design to allow both automatic switching at desired times and manual override. In general this system can be used for remote control of various home devices turned on/off by toggle or momentary switches. User interface is implemented as a simplistic web server. It’s certainly a reinvention of the wheel, but I just used this as an excuse to tinker with RaspberryPi, Arduino and wireless communication modules :)