My 2.5 year old son and I both love this app for him! He is loving playing with it while using it to practice finding letters by both name and by the sound they make, forming letters (tracing them with his finger), and even a little reading with choosing one out of two words for sentence completion and rhyming identification (although he cant read, he is hearing the words said aloud while paired with the written word in front of him- so very helpful for teaching him.) I totally recommend this app for preschoolers or precocious two year olds who are interested in letters and words. We use it on the iPhone 4S and the sound works great!!
Teebzs Momma about SUPER WHY!, v1.4