Company Lexpaper created these great apps:
Smart Flashcards - Addition 1, Smart Flashcards - Addition 2, Smart Flashcards - Subtraction 1, Smart Flashcards - Subtraction 2, Smart Flashcards - Multiplication 1, Smart Flashcards - Multiplication 2, Smart Flashcards - Division 1, Smart Flashcards - Division 2, and others..
