You can try Sample Tank, from IK Multimedia:
http://www.ikmultimedia.com/products/sampletankiphone/

I never used the iPad version, but running the PC one since 2010 with good results

Stefano


My band: www.tupamaros.it Our music: https://tupamaros-it.bandcamp.com/

Roland FA-07 - GSI Gemini Rack - Soprani Accordion - MIDI Drawbars controller (custom made)