Fantastic DIY for this weekend!
Now I've sold my AppleTV, the hardest part is handle with the SmartTV, the remote control and the onscreen keyboard.
With this project you can send content from your mobile. It is based on the use of various technologies with success, especially with Raspbian like operating system and various applications such omxplayer or youtube-dl among others and Chromium running in the background.
A little further along, but worth it.