It handles slash chords (D/F♯), sevenths, sus, add, dim and the rest, and it uses sharps or flats to match the key you're moving to. If a line is mostly words, it's left alone, so "A" in a lyric doesn't turn into "B".
Chartless listens to whatever is playing and shows the chords live, and its capo advisor (part of Pro) tells you where to put the capo so the shapes stay easy. Handy when the worship leader moves the song down a whole step at soundcheck.
More: transpose chart · capo chart · chords in every key · all guides.