Traditional ear training progams typically let you guess scales, chords, and intervals "as is". While this can be useful, a lot of people don't find it musical.
Functional Ear Trainer is different. The user can select a key and the computer will play a cadence to clearly define the particular key, followed by a random note. The user must then guess the note within this harmonic context.
With a week or two of practice, it will improve your musical ear a lot (at least it worked for me!).
Although I did not invent this concept, I think Functional Ear Trainer is the first computer program to implement this kind of ear training exercises.