@Harry-0 Welcome to Lingvist A major part of this site clearly are the courses. But there's a lot more to it than just taking a list of words and "automating it a little bit". For example, the words that are taught in a course are chosen by linguists and experts for the respective language.
The cards are reviewed in a SRS, a spaced repetition system. Shortly that means the more often you answered a card correctly, the longer it will take until it's asked again. But there's a lot of science behind the details so the SRS can hit what I'd like call the sweet spot - when your brain needs to invest some effort to remember the correct answer, but still hasn't completely forgotten.
If you choose to buy Lingvist Unlimited, you get access to additional features. For example, there are additional focuses that concentrate on different topics. For example, the German - English course offers several additional hundred words on "Business" in a focus, and several hundred additional words on "Living abroad" in another. The English - French course offers a focus on "A weekend in Paris", and so forth.
Plus, there are challenges. That are small exercises of different kinds. For example, you read a text or listen to a short audio clip, and then answer a question about it. In other challenges you're asked to insert the correct grammatical form of a word into a sentence. There are even challenges where you're using the microphone of your phone to record one part of a short dialog and work on your pronounciation.