Can't recommend anki flash cards enough. One thing that I found important is that you need to build the deck yourself and you'll miss out a lot by using prebaked decks of any kind. Reasons:

- Context is the king. Most of the words have multiple meanings and it's easier to remember them if you just added them from a text you've read. Moreover, this approach gives you an opportunity to see the words being used in the wild which gives confidence on when to use the word/idiom - Words with no context are just harder to learn - 3rd party decks will give you loads of words you don't care about

For learning French I've found kwiziq much more useful. Very little gamifications and lots and lots of training and exercises with examples that actually make sense