GitPlex can show history of any path (a file or directory) quickly via history button, and from there you can even refine the history (search for certain tags, commits made by certain people, etc) of the file, and once you get to the point, you can either view content of the file, or hit the compare button to compare with your previous browsed copy.
An example here:
http://gitplex.pmease.com/demo/android-framework-base/commit...