This Android app lets you classify Galaxy Zoo subjects. It is available in the Google Play Store: https://play.google.com/store/apps/details?id=com.murrayc.galaxyzoo.app . Try beta versions early here: https://play.google.com/apps/testing/com.murrayc.galaxyzoo.app . See also the iPhone app for Galaxy Zoo: https://github.com/murraycu/ios-galaxyzoo/
There has been one crash report with this (deobfuscated) backtrace, in version 1.40 on Android 3.2:
This seems to be happening somewhere in SyncAdapter.doRegularTasks(). It suggests a leaked Cursor, but I can't find any there that are not closed: https://github.com/murraycu/android-galaxyzoo/blob/master/app/src/main/java/com/murrayc/galaxyzoo/app/syncadapter/SyncAdapter.java