Lang-8 is a bit different from most language learning communities. In this one, you have your own journal and it is via this journal that you practise your language. You write posts about whatever you wish, and native speakers will correct you. You have a notebook into which you can bookmark corrections that you found specifically helpful. You can, as usual, search for people that match you linguistically, and language "partners" will also be suggested by the site itself. The people that are your friends will always see when you have written something new, so corrections often arrive fast. All comments need not be corrections though, you can simply add friendly comments to posts that interest you as well, and this may give a feeling of actually "using" the language, not only doing a "task"