If your meaning the one with 19 elements (20 if you include eraser) displayed in two rows on the bottom, than I think you have reached the simplest version. I can't guarantee it, but I am almost certain that that version is the original. Plypencil (a user on the forum) did something with the creation/development/testing of the original version, he can probably tell you if there is anything simpler.
ButtsexV2 The one on Geeks3D was the last release by the original developer, it was version 24, I believe. There were versions release before that, without elements such as Plutonium and Neutrons.