Here is my 2 cents... the best app for playing back tracks, hands down.
Android and now IOS too.

It has the absolute best gm wavetable. You can edit and save easily, built in mixer, search feature, and will play back any file. SMF, wave, MP3, also MP4 and other video formats.. and the only CDG zip file play with full key and tempo functions.

Song list features are unlimited..

Check it out.. less than $10 for Pro version.

https://play.google.com/store/apps/details?id=com.promusicsoftware.winlivepro



Here is a demo I recorded using the WinLive wav table..

https://app.box.com/s/q9lmnkn1xq2d2vr3u3swga1aa6sfr1yq