适用于手机和平板电脑的Android应用：1或2个应用？

I have to develop an application for both Android phones as tablets. The application logic is the same, while the UI is completely different. I'm wondering how I should deal with this: make 1 big app for both, or an app for phone and an app for tablet (and then upload the 2 apk's as 1 app in the market).I have to develop an application for both Andro