Functional ear trainer
Functional ear training is learning to identify notes by their scale degree (i.e, what note they are in the major or minor scale). It's an alternative to typical ear training that's based around identifying relative intervals between notes, and can be used to quickly recognise and transcribe melodies.
It works by playing an initial 'cadence' (or chord progression) to get the scale's key 'in your ear'. It then plays a note from the scale and it's your job to identify the note played by scale degree.
I recently became interested in training my ear but I couldn't find an application that connected to my keyboard through midi, so I quickly threw this one together. It supports any key, notes from a single octave or any octave, playback of multiple notes, and more. It trains you to recognise the scale degrees of notes within a key.