Good for younger kids
Great flashcard app
Why would you want a reading app that talks!?
You can focus on each set in order, and check how many your kid got right/wrong. That's also good.
However, if you tap the word, THE IPAD READS THE WORD ALOUD. Why would anyone want this as a feature on an app that solely focuses on the reading mastery of a specific supply of words? There is no evidence or research to support that having those words read aloud nets any positive learning; on the contrary, the immediate gratification of having those words read out loud circumvents any real attempt to decipher the word, promoting instead a reliance on memorization which is NOT recommended to achieve grade-based fluency.
TL;DR: If you buy this app, then mute your iPad and don't tell the kid.