The 1.6 version of Lockr for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The actual developer of this free software for Mac is YKA SAS. The program relates to System Tools.
From the developer:
Lockr is an application that allows you to transfer your files very quickly and securely. This free application is an extension of the lockr.ch website. You can add notes to every file transfer. Lockr lives in your menu bar and has an user friendly interface.
You may want to check out more software for Mac, such as pdf-FieldMerge or Catenator, which might be similar to Lockr.