Word Meaning builds your vocabulary one useful word at a time. Pick the closest meaning, then see the word in a real example sentence so you remember how to use it.
Right after learning a word, say a sentence with it - that is how it moves into memory.
Un- means not (unwilling), -less means without (careless).
The results screen lists words you missed - play again tomorrow and see if you remember them.
What level are the words?
Why the example sentences?
Is it free?