This website helps recognize different scales by ear, without looking at what key it's in. This also helps greatly with hearing different trichords, harmonics, and melodic scales.
This site lets you practice identifying scales, chords, intervals, and chord inversions. There is also an app on the App Store that I'm pretty sure is free.
This website has practice exercises for everything from note dictation and clef reading to harmonic progressions and the construction and identification of seventh chords. The "exercise" page, which this link goes directly to, houses all of the practice resources.
This is a comprehensive study guide for many concepts within music theory. Given specific parameters, it will generate specific scales, key signatures, etc. It also has manuscript paper, glossary of vocab terms, and more.
So this site has a variety of different intervals, scales, chords, and some melodies that you can use to help you identify the different names of intervals, notes andmelodies. Also has a perfect pitch trainer to help you work on your inner ear.
This website lists intervals and shows them on the treble clef. There are also tabs on the side to notation, rhythm, meter, tempo, musical form, scales, chords, and harmony.