The zip archive will unpack to a folder called "davescale-OSX" or "davescale-windows10". Inside is the "davescale.app" (OSX) or the "davescale.exe" (Windows) executable you can run.

NOTE: If you create your own scale and write it to a file, when you read the file back in, you need to click on the "my scale!" option listed at the bottom of the different pre-set scales, even if it is already selected.

You can also edit your scale files 'by hand'. The format is:

key#, frequency;
key#, frequency;
key#, frequency;
key#, frequency;
...

1, 100;
2, 200;
3, 300;
4, 400;
5, 500;
6, 600;
7, 700;