docTrackr is described as 'Encrypt your documents - regardless of recipient, device or location. Protection travels with your files. Remotely manage your secured documents, even destroy them after they're shared'. There are five alternatives to docTrackr for Online / Web-based, Windows, Mac and SaaS. The best alternative is pitchXO. Other great apps like docTrackr are DocSend (Paid), CapLinked FileProtect (Paid), FileOpen RightsManager (Paid) and Clearslide (Paid).
DocSend makes business communication with documents more effective and actionable by providing analytics, feedback, and control for the documents you send. Hundreds of companies use DocSend for everything from sales and marketing to fundraising.
FileProtect provides a secure digital rights management (DRM) wrapper around all your sensitive files, including Adobe PDF and Microsoft Office (Word, Excel, Powerpoint). With FileProtect, there are no plugins to install or update — it all just works.
FileOpen RightsManager is a client/server solution for encrypting and managing access to documents from your desktop. With RightsManager, you encrypt your documents locally, so there is no need to upload unencrypted documents to an unknown server.