OffBlock 1.17.3 for Mac could be downloaded from 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 application lies within Business Tools, more precisely Project Management. This Mac application was originally designed by Peter Seifert.
From the developer:
OffBlock is a Mac OS X application that allows you to keep track of your flights.
You may want to check out more Mac applications, such as iBiz, Conjure or Minco, which might be related to OffBlock.