It's called GCodeSimulator.

GCodeSimulator

Unfortunately when I first tested it on my BfB Rapman Gcodes it didn't work as expected.
While on my CreatR Leapfrog Gcodes (generated with Slic3r) it worked like a charm.

I know that these two machines are not using the same Gcodes and that BfB Rapman Gcode is a bit different from the usual Gcodes used by most of the printers on the market.
So I decided to contact the coder behind this little gem (Mathias) just to let him know about that.

Mathias was kind enough to answer me he would also like to support BfB Gcode within the simulator and asked me if I could provide him with some BfB example Gcode files, which I did.

And after a bit of rework of his program he managed to do it !
So it's now also possible for BfB machines owners to check their Gcode files with the help of this very useful utility that GCodeSimulator is (V1.24). You can also invoke the simulator directly from Kisslicer by adding it into the "Post-Process" field under the "Printer/firmware" tab.

Many thanks Mathias !