Dropr is integrated seamlessly into the post editor. With a click on Dropr button you can access all your Dropbox files right from your WordPress site.
Click on the 
button in content editor to get started. If you have an API key configured already, Dropbox’s chooser window will open up. Using the window you can upload a local file or choose an existing file from your Dropbox account.
You can upload files to your Dropbox account by just dragging and dropping them to the chooser window from your computer. Alternatively, you can also upload files by clicking the ‘+’ button in the Dropbox Chooser window.