How many of you use SRS? How many of you know what SRS is?
Simply, SRS is a digital equivalent of study flash cards. The idea being that information you want to retain get's written on a card with the answer on the other side (eg Side 1 ="What is a preposition?" Side 2 ="A word that usually precedes a noun that expresses a relation to another word in the sentence").
Flash cards are a great way to study but the software equivalents go so much further and the system is based on reviewing the information at set intervals. A card you memorize today will be shown again tomorrow and then if you answer it correctly then it will show it again but... in 3 days time, then 10 days etc. The idea is it will show you the card just as you are about to forget it so you can keep the information in your head while only using as much time as is necessary (highly efficient!)
There are several pieces of software out there that do this (some online) as well as mobile apps. My favourite is ANKI because of the amount of customisation you can do. You can change the look of cards, add media such as pictures and even audio (which is great for practising accent etc). There are also many plugins that allow you to change the look of and the way the program acts.
You can't "learn" a language through ANKI. You still have to learn grammar concepts and understand them, figure out why sentences work a certain way but what SRS helps you to do is retain this information and retain it very efficiently. That being said if you have never used software like this before then it is worth checking out!