LDSSingAlong.com. They did a great job. They offer a version with Hymns and one with Children's Songs. Both are available in Spanish. You can download the lite version for free to try it out. Each song has a handful of high quality background pictures to choose from and the music is from the recordings done by the church.
I taught my primary kids "I Am a Child of God" in Spanish by pointing to the words on a poster (can't believe how fast they picked it up) but boy, I wish I had this app hooked up to a big tv or projector! I'm working on getting the right chord to connect my iPad mini up to the new tv our building just got, then watch out, Primary Kids, we're going to learn all kinds of songs in Spanish!
Click on the video below to see how it works!