Someone else recently posted about this app but that card seems to have disappeared. It is a language learning app which allows you to talk to native speakers of the language you want to learn who are learning your language so you can help each other and practice together. I know that plenty of people here are trying to learn Korean so you may find it very helpful. I'm currently learning Chinese not Korean but I assume it is just as useful for Korean. I downloaded Hello Talk and started using it yesterday. So far I have learned several new words from very friendly, very helpful people.
To the person who posted the card that mentioned this app a day or two ago: thank you! I am so glad to have found out about it!