Swar Systems has published a new update (1.0.2) of SwarPlug its virtual Indian instrument for iPad - - that now supports Audiobus and Inter App Audio (IAA). This further expands the possibilities of routing the audio flow from the synth to and through any effect or target audio app.
SwarPlug is an Audio Unit Extension (AUv3) synth that features up to 79 Indian voices through In App Purchases (Tabla included by default). It is available directly from the App Store.
Here is a link to a short video introduction: http://www.swarsystems.com/support/videos/index.php?v=601