PathSync is a freeware app that can analyze two directories and show you a list of differences between the directories.
The interface fo PathSync is easy to use. Select your local and remote folders, default synchronization, then narrow down the differences you're looking for.
You can ignore file sizes, dates, missing local files and missing remote files. Logging is also optionally available.
By default, folder syncing is on; after all, that would be the most common use for PathSync. Otherwise, there's a Synchronize! button at the bottom right to synchronize when you want. You can also right-click on any items in the list to change the default actions. these include Local -> Remote, Remote -> Local, No Action, and more.
After you synchronize or compare, a status window will break down what was found or changed
If you're looking to keep folders in sync, PathSync is hard to beat. It's tiny and completely free.