The is and executable file of the Java applet for those that do not have or want a JRE installed.

INSTALLATION:
1. Unzip
2. Run exe

The file does not need to be installed and it is not relevant where you place it. Desktop is just fine for example.

When you run the file you will probably get a notification that it is from an unknown publisher, which of course it is.
There is nothing dubious about the contents of this, I can't think of any other way of making this app a standalone.

If you don't trust the exe then download and use the Jar version which does exactly the same thing, but you will need a JRE for it to work.

TECHNIACAL:
Jar file which has been wrapped into a mini JRE for standalone use.