Sigue tus series
My first ruby on rails project and a personal itch scratched. At that time I watched lots of tv shows, and I had some trouble keeping up with what had I seen and what not, so I made a web app to keep the shows that I watched monitored for new episodes.
It would alert the user when the shows had new chapters, and it let him add new shows to follow, etc.
The version visible at the screenshots is the v2 of the frontend.