This Java, English trainer was made especially for my girlfriend. Nevertheless, anyone can use it. (Language: German)
This English trainer can query vocabulary, can export and import entered vocabulary so that you don't have to enter it again and again.
It also has translation from German to English and vice versa (Google translated, as I couldn't get to the DeepL API).
Just start the jar file with Java 8 or higher and have fun with your new English trainer in Java.