You can add a desktop icon by using the appropriate directory to copy the file
to, run as root, and edit to correct the directory path. Below are generic directions.

Download the 3 files: cin.svg, cin.xpm, and cin.desktop from folder Desktop_icon.
Copy those 3 files to the locations shown below.  In some instances you may have
to copy to a local area instead of /usr/share... .

cp -a cin.svg /usr/share/pixmaps/
cp -a cin.xpm /usr/share/pixmaps/
cp -a cin.desktop /usr/share/applications/cin.desktop

After you have copied the above, in the cin.desktop file, change the Exec=cin
line to be Exec=<your_directory_path/filename.AppImage or /bin/cin> substituting
your actual CinGG AppImage or filename to include path and without the < and >. 
You may also have to chmod +x.