Goto last change in current buffer. Repeat to go to earlier changes. Negative arg to go back to more recent changes. With argument 0 (C-u 0) you get a description of the change that was done at every changed position.
This function uses undo information.
Another package that do a similar thing is goto-last-change.el (GotoLastChange) by Kevin Rodgers.
Another package I have not tested is UndoBrowse by DeepakGoel