We developed a native interface for smartphone based on Android v. 2.2 and v. 2.3 version.
It implements some basics functions of a Moodle platform for the student role:
0) login (normal login account)
1) read the list of your course
2) see your calendar
3) see your grades
4) see the resources (PDF, doc, xls, ppt, txt)
5) read the forums and reply to a post
6) see the list of participants
It relies on the package of OKTech webservice (http://docs.moodle.org/20/en/Web_Services:OK_Tech_Web_Services#Installation).
If useful, we could share it (it is a joint project of eLab - USI and SUPSI http://www.elearninglab.org/ and Faculty of Informatics at USI http://www.inf.usi.ch/), let us know.