It's a .zip file. I've unzipped the file, and two folders and two other files show up, one folder is labelled MACOS and so is one of the files, the other folder is labelled KALD.apphas a list of files, and the othe file just says KALD.app
I've tried selecting all the files and dropping them into the iTunes app library, and I've tried adding the .zip file via 'Add a file' in the iTune's menu.