Measuring the interval is straightforward in this app. If you change the height of the note, the interval is automatically measured. You can also study in a more systematic way because the number of semitones appears along with the name of the interval.
Once you become more familiar with music intervals, try solving some interval questions. Interval questions are shown on the score and the keyboard. Even if you are not familiar with intervals, you can answer the questions easily by counting the semitones of the two notes on the keyboard.
You can also try “Interval Sight Singing”.
Hopefully, this app will help you to study music well. Thank you! :)