I really recommend Torii. 
It’s free, with a desktop and Android version. Made by a WK level 60 user, so you can also use WK mode - which excludes any core 10K terms that are covered in WK so that you’re not learning things double.
Audio of simple example sentences with each item means you can also practice some grammar and listening while you go through the lists.
You can also set it to be tested both JP → EN, and ENG → JP, so both recognition and recall can be worked on if that’s what you want.
There is also FloFlo - a website that generates word lists for Japanese books. There are some free online books linked there. It’s meant to SRS vocab so that you can then more easily get stuck into a book while already knowing a lot of the vocab, so you don’t have to stop every 2 seconds to look something up. You can filter words based on frequency. Freq 1 for every word in the book, and freq 3, for example, for words that only appear three times or more. That way you know that any unfamiliar word you encounter only shows up once or twice.