Palace guide minimally helpful
It more or less repeats the signage with very small amounts of additional info. (And in excruciatingly tiny print.). It might be helpful if the lines are long and you couldn’t see the signage.
In addition, it is not fully functional: the audio portion and the mapping portion described in the instructions did not operate at all.
In fairness it was free. There seemed to be one that could be purchased that might have additional info.