Hi,
I was in the same boat trying to find a good equivalent for iTunes U and I think I've found it.
Backstory:
http://www.the-digital-reader.com/20.../#.UGUnWcXTanI
Actual App:
http://tunesviewer.sourceforge.net/
I went to the actual app site from my phone, and click on the .apk and installed it that way. (Make sure you check 'allow unknown sources' in your settings prior to installing). Anyway, I opened it up and it matches iTunes U exactly (I've been updating my iPod and iPad most of this evening, so I meandered over to the iTunes U while there and it does match the classes.
Make sure you set the download directory.