This version is contained within a disk image (.dmg) in the convention of macOS software releases. The aim of doing this is o make it simple to include on an external storage medium (along with your other diagnostic & troubleshooting tools) and run it the same way on any mac you plug your drive in to.
Keep in mind that currently, the paths to the resources this program relies on are hard-coded, so if you decide you like this program and want to move it off of the disk image, all of the functions may not run as expected. I am planning to release a more portable version in the future, so stay tuned. For now, just make your life easier and run it off the disk image 👍