There's a caffeine version and a non-caffeine version. We won't know what separates it from other products on the market until they release the label publicly and we know the ingredients. Some possible suspects: ginkgo, bacopa, vinpocetine, huperzine A, gotu kola, etc.
I don't think Biotest ever said anything about increased muscle gains taking this supplement. It could do that indirectly, however, from increased mood/energy/focus/whatever and thus better performance in the gym.