A great language learning website. It's based on reciprocal correction of diaries written in the target language. You can use the free version or paid version. The latter gets rid of the ads, along with a few other privileges such as being able to download the diaries as a PDF.
One minor improvement (which may have been fixed already) is that the downloadable PDFs should be customisable so that don't take up so many pages of paper. As a non-programmer I don't know whether this is possible.
There are a few people who abuse the site as well. I remember seeing one guy on there who had had 300 Italian diaries corrected by kind Italian people trying to help. None of them had noticed that he had *never* helped anyone in return. I think the site is trying to encourage users to reciprocate as much as possible, though, given some recent changes they've made which prompt users to that effect.