I use memrise. This way I was able to learn about ~4500 words in a year. And I started at a very low pace. I don't recommand using the android version for korean but using the website instead. You can fix daily goal, you have a leader board and a badge if you study for consecutive days. For me it just solved the vocabulary issue. But it's not enough for hard words. You will learn its definition and how it sound but not its usage. If you want to stick it to your memory you should use them in sentences. For that I use hinative. You can ask quick question like "is this sentence natural" and people correct you pretty fast.

There's a lot of advice out there for learning more common languages like Spanish and French. I've been taking some of those tips and applying them to Korean where I can [as most language learning tips are pretty general]... So, alongside what most people have said about practicing usage, try reading some kids' books. http://unyounglearnskorean.tumblr.com/post/100930792028/childrens-books-in-korean You can try labeling things around your house in Korean and referring to them by those names. There's also quizlet.com. I don't know how much it costs for personal use, but I use it for one of my Korean classes and it has several different ways of learning vocab lists - including games.

There really isn't a short cut to memorizing, however these few steps have worked fine for me. 1. Mapping - I am presently learning Korean language and I realized that when I am able to link the sound of a new word to a scenario or a word in my mother tongue, I tend to remember it faster. 2. Memorizing words in isolation is also tedious, thus not highly recommended. As much as possible try to memorize interesting and funny sentences or phrases. You learn both words and grammar at the same time by this method. 3. Use what you have learned. Over time i realize that when I work out to develop muscles and I do not put them to use, I loose it all again. It is the same with memorizing words. If you do not use them in real conversations, you easily forget them too. I hope these help. If you find a better approach I will be glad to give it (them) a try. All the best.

Memrise, Memrise and more Memrise!