Shamisen Player (Pro) features a simple virtual Sao (the neck of a Shamisen) covering a useful first octave of the actual instrument's range on each of the strings.
Of course authentic sounds are used that were recorded from a real Shamisen.
All of the playable notes are obviously numbered (including 3# and 10b) corresponding to standard finger positions and tabulature notation.
All of the three common Shamisen tunings are available.
Star shaped buttons just below the virtual Sao are featuring additional cool sounds (Taiko drums and relaxing natural background tracks).
One of the star buttons takes you to the menu where you can choose another tuning and also get to an introduction to the Shamisen featuring a glossary of Japanese terms and a first playing lesson with tabulature of a very famous traditional tune.
Of course the app is also and especially good for finding melodies of your own on the go.
Go Play . . . :)