As a bit of an early demo, I've put together a video showing a proof-of-concept that uses hardware integration.
The Android tablet I'm using is a Motorola Xoom, which is currently running Android 4.1.2. This is hooked up to my Korg M3 keyboard, which provides MIDI over USB (in addition to standard MIDI I/O), via a host mode / OTG ("On-the-Go") cable.
Normally, my tablet acts as a peripheral device to be plugged into a host computer (e.g. desktop or notebook); with Android 3.2 and later, the tablet's single USB port can act as the host so that other USB peripherals (e.g. keyboards, cameras) can be used directly with the tablet. The adapter cable provides a standard full-size USB socket for my M3 (in this case) to be plugged into.
This demonstration shows the tablet responding to incoming MIDI data from the keyboard, by lighting the keys of the on-screen keyboard in real time. This is needed for eConcerto to track what the musician is playing. The sync functionality causes MIDI data to be sent in the opposite direction, causing a 'C' note to be played repeatedly. When notes on the keyboard are played in sync, the average latency is calculated for use in performance mode. This allows other MIDI channels to be activated on the keyboard in time with the live performance.
Anyway, on to the video: