Always a word or two not introduced in the lesson on the app
For example, lesson 3 of Occupations in the German tree. Geschäftsfüher was not introduced in the lesson. Another example is lesson 3 of Travel in the German tree. Sehenswürdigkeit was not introduced in the lesson. I do not want to have to go on google to search up what the word means.
If you don't want to Google it, ask the community, ask for information about that specific word, look up german online dictionaries, and so on :)