application for android and iPhone devices

we work in a school and we create flashcards for our students in order to learn new vocabulary. the flashcard is printed and has a sentence with a word missing (or an image describing the word missing) and the student has to find what word is missing. the word that is missing is also printed with small letters on the back of that flashcard. so we have a database with all those sentences and answers and we need to create a new application where we will organise those flashcards for different topics and lessons (e.g. group together 30 fruit images and sentences) and export them in doc or/and pdf on a very specific format which is attached below.