Input a key, figured bass, and given bass note, then hit "search" to see the Roman numeral, chordal members, and doubling rules!
N.B. This program will only return iiø7 (ii half-diminished seven). Remember to lower the seventh scale degree further if iiº7 (ii fully-diminished seven) is required. This program will only return results for seventh chords with dominant function (V7/viiº7 and their inversions) and those built on scale degree 2 (ii7 in major, iiø7 in minor) since they are typically the only ones found on the AP Music Theory exam.