This app has a wonderfully expansive and thorough set of ear-training exercises. It’s also very easy-to-use. I honestly can’t imagine a better app for ear training.
My only complaint is that I wish it had more exercises for identifying chord progressions (deceptive cadence, Phrygian half-cadence, Neapolitan, Fr. vs. Gr. vs. It. aug6, deceptively resolved aug6, enharmonically resolved fully diminished 7, etc.).
Brett Wines about Ear Trainer, v2.5