MacDropAny is a simple app that painlessly allows Mac users to sync any folder on their computer through Dropbox. To sync another folder, either drag and drop a folder onto the MacDropAny icon, or just run the application as you would for any other application, then follow the on-screen instructions.

Author's Note: MacDropAny will not allow you to sync your Applications folder or your iPhoto library, as this tends to lead to large problems for the user. If you are sure you know what you are doing, you can enable syncing of these folders by running defaults write com.zibity.macdropany mode expert.

Requirements:
OS X 10.10+
Dropbox Account
64-bit Intel

Also available are:
Intel version 2.14 for OS X 10.8-10.9
Intel version 2.12 for OS X 10.5-10.8