Maybe you've created your own AR program for wearables that shows the definition of a word when you highlight it IRL, or you've built a personal calendar app for your family to display on a monitor in the kitchen. Whatever it is, I'd love to hear it.
I used a Raspberry Pi with a Hifi-berry card to make a web-controlled MP3 player hooked up to my stereo. It's a fairly bare-bones app but I wrote it myself (Flask, VLC) and it works great!