They're in English, but and this is a big BUT, you can customize the photos, text and the sound recordings. I downloaded the "I Like Colors" book and yes, I was able to customize it using my own voice and text turning it into a Spanish picture book. (I haven't tried changing the photos yet, because I wanted to get the word out as quickly as possible about this app!)
From the site:
All “I Like” Picture Books contain engaging stories written by Miranda Paul and stunning crisp photographs. Words are highlighted as they are being read to optimize the learning curve. Literally everything is customizable; add your own voice, your own photos and even your own story line!
There are other free ones as well such as I Like Numbers, I Like Grandpa, I Like School, I Like Planes and several more.