Readlang is a website created by Steve Ridout that helps you learn foreign languages (35 languages possible!) by reading and translating words you don't know.
There is also a video to see how it works. It is said to be now out of date, but more information is on the website.
On the website, first you set your native language, then set the language you’re learning. Then insert a text. A text can be cut and pasted onto the website, or a link can be uploaded. You can even upload an entire novel. I tried it with the first paragraph of an article I used with my students this past semester (see my last blog post, Self-parking automobiles), marking German as “my language” and English as the language I’m learning.
When the text is on Readlang, you can put your cursor on a word, and it is translated into your own language. The only problem I had with this is that you can only translate one word – not a lexical chunk (like “according to”) or idiomatic phrases (“just around the corner”). And, as we all know, one-to-one translation doesn’t always work very well. But for a fast and easy vocabulary check, my students will probably like to use this.
A useful feature is that all the words that you have chosen to translate are then stored in the area called “Learn”, where you can test yourself (like using flash cards). There’s also an area called “Words”, which gives more information about each of the words chosen. The text itself is stored in “Library.”
The site also has a blog where Steve Ridout gives more information about how to use the site, and gives further updates on the site’s progress.
The blog: http://blog.readlang.com/