To master interval recognition, I suggest to check out the app prepared by myself.
What makes it easier for guitarists is the nomenclature based on the number of frets (number of semitones).
Another advantage for guitarists is the choice of guitar sounds.
The visualization for now is only in the form of a piano, but in the future there will be also a visualization of guitar's frets. This app is a fresh project and it's still 100% free, so you will have to wait some time for the guitar visualization.
Nevertheless, I think that ear training itself can already be fully realized through a reliable practice of a few minutes every day.
Have fun!
JJozwiak.
Translated with www.DeepL.com/Translator (free version)
