Things I love about it:
1. You can customize the background to any image.
2. You can link a YouTube video to play when the timer goes off.
3. I was able to add a picture from Barcelona, Spain during "La Navidad" and a Spanish carol available from YouTube to play when the timer went off. It was a simple way to integrate a bit of culture into the lesson!
One tip - I pinned this Chrome app in my browser to have ready whenever I need to use it!