You could have downloaded iShrink 3.0.4 for Mac from our application library for free. The most popular version among the application users is 3.0. The bundle id for this app is com.littlevishapps.ishrink. The actual developer of this software for Mac is CodeFuzion Inc. The program is included in System Tools. The program's installation file is generally known as iShrink.dmg.
From the developer:
iShrink is a program that can compress or decompress in standard Zip format, Unix tar Compress, tar Bzip2, and tar Gzip. It can create multi-file archives. The files contained in these multi-file archives can be deleted or updated, and you can also add more files to these archives or preview the contents at any time.
iShrink allows you to open or extract files contained in your archives.
You may want to check out more Mac applications, such as StuffIt Expander, which might be similar to iShrink.