Well done, very professional looking app. I did not have a sound issue in iOS6 (however, it would sometimes close "by itself" but not enough to be annoying). The video lessons with Maurice are somewhat short, but well done, and then after each lesson there are fun (and sometimes very challenging) games. Only one complaint is that I do wish there were more examples in the videos. Because there are not so many examples, doing some of the medium to hard exercises would be rather difficult for a "true" beginner (someone who knows nothing about chess and is trying to learn chess alone from this app). A true beginner would have to supplement the app with other sources like a basics tactics app. However, with this said, one can tell that a lot of time and effort went into producing this app and for $2.99 its in my opinion worh it.
Teacher dad. about Learn Chess! with Maurice Ashley