Launching gui apps on Linux remotely can be easy as
$ ssh -X test1.example.com
Back in the bad old days of Unix when X Windows was first being developed, it was decided that having the ability to remote into a machine and launch graphical apps was a good idea. All versions of X11 have retained this capability to one degree or another, but it's one of the features dropped by the Wayland project.
You need a few prerequisite packages for this to work, but the following are the bare minimum:
xauth
xorg
xterm
In my last fresh install of Ubuntu Server, xauth was already installed. Installing the other two should also install the balance of the required prerequistes ("xorg" is a big meta package that contains most of it).
One of the arguments made against remote X sessions is that they aren't secure. That's true, if you use the native
facility in X. But it is not if you use an ssh tunnel: which is exactly what the ssh -X command does.
In practice you'll find it's best to open one xterm remotely, and then launch a second from within it. This way you can launch and potentially kill additional X apps (like, say, Chrome) from the second xterm without having to connect all over again.
This article contains a fairly complete discussion of alternatives for running gui apps remotely on Ubuntu Server, and is worth a read if you're just starting out: Server GUI.