Currently there is no stand-alone installer. You have to run gsimcli as a Python script, launching the file interface/gui.py.
Only Python 2.7 was tested. It should be easy to port to Python 3.2+ if all dependencies are already available to that same version.
Note
pandas has a list of dependencies, some mandatory, other recommended and some other just optional. Although, you are highly encouraged to install all of them as they may be necessary in GSIMCLI.
Although, if you installed Python through a packaged distribution, chances are that you already have those libraries.