I LOVE Yugioh, and this is my go to app when I want to look at Yugioh cards. There is this Ygolite app for the iOS, but it doesnt provide pictures or easy Deckbuilding. The only problem with this I would say is the Duel function, which is really annoying for me to keep drawing cards and putting them back so that I could a card out. Either way, I still love this app.
SuperMutant105 about Yugipedia Deck Builder for YuGiOh, v1.8.1