If you go into security options on your phone there should be an option to "allow installing from unknown sources" or something to that effect, then when you download the APK you can tap it and it will install manually
TCG live is an online version of the actual TCG. The primary way to unlock cards is to buy the physical cards as there is no monetization at all. You can still get cards without but much less.Like I said it's the actual game. Pocket is a much simplified version.Live has 60 card decks vs 20 from PocketAnother major difference is Winning in Live you have prize cards. Where after you draw your iirc 8 cards you put 6 cards off to the side. You get these cards into your hand by defeating pokemon once you reclaim all 6 you win.Further difference is the need to have energy cards in your deck. Meaning you are limited in how much energy you have.Live is also more prone to crashes & bugs. Like I said the service has absolutely zero monetization so less incentive to fix bugs when it works pretty good 80% of the time (exaggeration)Pocket is about collecting Live is for battles.Pocket matches last like 10 minutes Live is easily 20.