Card rarity in Pokmon TCG Pocket works similarly to the traditional card game, but there is some variation in the symbols
205.4 Players may include cards from any printing in their constructed decks if those cards appear in sets allowed in that format (or those cards are specifically allowed by the Magic Tournament Rules)
Its effects happen at the beginning of each end step , so they also work on your opponent's end steps
As long as neither player is manipulating their library or using their graveyard, using a Millstone does nothing but reveal information until the player being milled runs out of cards, but it took more explanation than you can possibly imagine to make players understand this
Tool cards represent items held by Pokmon, like Leftovers which helps to restore HP periodically
You may find lots of unofficial metal Pokemon cards for sale online, so if you find one that isnt one of the four officially released cards, unfortunately it does mean its a fake