How do I close or delete my Orangedox account? I don't seem to see that option in my account settings.
You can remove Orangedox as an application from your Dropbox. Here's an article that gives you step by step instructions on how to do that.
Note that any links that you've created to folders or PDF's using the Business or Pro products will cease to function. While any links you've created as a Basic user will continue to work.
If you like you can remove the links within Orangedox first.