Spaced repetition is a learning technique that integrates growing intervals of time between consecutive reviews of materials that were learnt before, so that an order feets into the psychological spacing effect. This is a glamour way of saying that you review flashcards within a progressively growing intervals of time. So, if you’d try to remember the Japanese word for friend, “tomodachi” (朋友), with a Spaced Repetition Software, firstly, you’d review that word and have an option of re-reviewing it right now, in 15 minutes, or three days later (you can customize it with your own preferences).
When you are to review it next time, there will be an option to review it for a third time thereafter with longer time intervals (for example, 20m, 6d, 10d, or 13d), and so on. After some period of time, let’s just after a few months, you’ll end up reviewing the same word from 4 to 5 times at the very least. This will ensure that the information will be ‘nailed’ in your long-term memory. Reviewing and repeating are important for a memorization, and we encourage you to try it out.
Our team have been using this method personally for over a year to learn thousands of new words and sentences. You can find free apps for your PC or a smartphone, but usually apps for Android or Apple phones aren’t free and may cost you some money. Nevertheless, some apps have web versions, which are awesome because they let you use your flashcards on any device you prefer, from anywhere around the world, and after every study session ends, it synchronizes all of your decks that you have installed on other PCs/devices, in order to keep them updated.
We suggest using apps in the way so that you’d be able to take words that you come across in your life or studies, and write on one side the word in the language you want learn, and on the other side there will be a definition (for intermediates, we suggest to write definitions in the target language as well), using from 2 to 4 examples or sentences. Good sentences and examples can be found via dictionaries, but it’s not a mandatory and you are free to get those from literally anywhere, a tv series, a book, a song or from a block - the choice is yours.