The 3.5 version of ArtLine 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 program lies within Design & Photo Tools, more precisely General.
From the developer:
ArtLine is a high performance vectorization and retouching application. You don't need to spend hours redesigning logos. Instead you can vectorized them with Artline. This means you can resize the image without loosing any image quality.