In Word Scramble you assemble a word from individual, jumbled letters. Unlike the quiz, you cannot pick the solution from given answers – you really have to be able to write the word letter by letter.
The app shows you a word to translate, and below it the letters of the solution in random order. Tap the letters one after another in the correct order until the word you are looking for is complete.
In the settings you decide which direction you are asked in. The setting applies jointly to Quiz, Word Scramble and Flashcards:
For actively mastering a language, "German first" is the more demanding route: you have to produce the foreign word yourself instead of merely recognising it.
You are not limited to the words that ship with the app. Using the camera import you can photograph a vocabulary list and have it turned directly into your own Word Scramble level – for example exactly the words from page 42 of your textbook.
Word Scramble specifically trains the spelling of foreign vocabulary. That makes it the ideal complement to the flashcards: there it is first about remembering the meaning, here about being able to write the word correctly as well.