Create the install directory from FastX tarball, link it to a common spot, and set permissions on it so everyone can read/execute:

cd /opt
tar xvzf ~/FastX3-3.2.16.rhel7.x86_64.tar.gz
mv /opt/FastX3 /opt/FastX3-3.2.16
ln -s /opt/FastX3-3.2.16 /opt/FastX3

chmod -R 755 /opt/FastX3/
chown -R root:root /opt/FastX3/

Create symlink to /usr/local/bin/FastX2 to add the launcher to everyone's PATH:

ln -s /opt/FastX3/FastX3 /usr/local/bin/FastX3

Create .desktop file at /usr/share/applications/FastX3.desktop with the contents:

[Desktop Entry]
Version=1.0
Name=FastX 3
Comment=Use FastX 3 to connect to workstations
Exec=/usr/local/bin/FastX3
Path=/opt/FastX3/
Icon=/usr/share/icons/mate/32x32/places/gtk-network.png
Terminal=false
Type=Application
Categories=Utility;

Set permissions on the .desktop file:

chmod 755 /usr/share/applications/FastX3.desktop
chown root:root /usr/share/applications/FastX3.desktop

Enjoy!