Apps similar to SeekerDLP include Spirion, which has a free version. Other options are Curtain e-locker. Between them they cover Windows, Linux and Mac.
Spirion accurately discovers, classifies and protects all of your sensitive data—from personal information to company confidential information—stored anywhere, in any format, and at any time.
Curtain e-locker is a powerful Data Loss Prevention (DLP) solution that secures sensitive electronic information within an organization. It controls and monitors user actions such as saving, copying, printing, and transferring files to prevent data
