The app is working on my iPad without any glitches. As an adult with no knowledge of the Yiddish alphabet, it’s a great way to practice reading the letters and learning their sounds. My only complaint is this: This app will play you a recording of the pronunciation of a letter (without showing you the letter), and you have to choose the correct letter. In Yiddish, certain letters produce the same sound. Sometimes the quiz will ask you to choose the letter that produces the “s” sound. It’ll provide you with 6 multiple choices, 2 of them might be sin, and samech, which both produce a similar sound. Or nun and Lange nun for the “n” sound. And when you’re only hearing the sound (without seeing the letter), it’s hard to distinguish which letter they want you to pick. There are multiple occasions when this occurs, and it can be discouraging when you’re first learning to be told you picked the wrong answer, when you technically did pick a correct answer. I will continue using the app regardless, but the developers may want to consider programming questions/answers so the user won’t have to choose between two answers that are both correct!