I would imagine your main problem is going to be legal rather than technical. The Apple Website's terms of use say:
Except as expressly provided in these Terms of Use, no part of the Site and no Content may be copied, reproduced, republished, uploaded, posted, publicly displayed, encoded, translated, transmitted or distributed in any way (including “mirroring”) to any other computer, server, Web site or other medium for publication or distribution or for any commercial enterprise, without Apple’s express prior written consent.
I'd be surprised if an iTunes Store Browser application passed Apple's approval process since the iPhone already has one and it's even more unlikely that Apple would let you use their content for an Android application.