Mandolin Tuner EM-1 app for iPhone and iPad
Alternate mandolin tunings (Piccolo/sopranino, Tenor/alto, Octave/mandola).
Adjustable reference note frequency (A440).
Automatic detection of tuned strings.
Most common chords with fingerings and string tones as quick reference.
Various note naming schemes: English (CDEFGAB), German (CDEFGAH), Latin (DoReMiFa...)