I've been brushing up on some of my Spanish recently, and found this excellent free application.
Duolingo is an excellent resource for learning languages, and it has one of the best user interfaces of all e-learning resources I've ever tried. From their website they state that;
We believe everyone should have access to education of the highest quality - for free.
The colours, feel and interactivity of the website is really well thought out, and users are guided through each step. The service is designed so that, as users progress through the lessons, they simultaneously help to translate websites and other online documents.
As of August 2014, Duolingo offers Latin American Spanish, French, German, Brazilian Portuguese, Italian, Dutch, Danish, and Irish courses for English speakers, as well as American English for Spanish, French, German, Portuguese, Italian, Dutch, Russian, Polish, Turkish, Hungarian, Romanian, Japanese, Hindi, Indonesian, and Korean speakers. It is available on the Web, iOS and Android platforms.
I've had to study e-learning recently for various reasons and this is by far the best designed, most intuitive and offers a great user experience. The teaching approach won't suit everybody, some of the phrases and sentences are a bit random ("The bear drinks milk"), although you have to understand that the whole idea is to get you used to constructing sentences, no matter how weird they may appear.
Some of the features Duolingo;
Gamification has been introduced into the learning experience, as it has on most decent e-learning platforms so you can collect points, share on social media, invite friends, earn badges and more. What I really liked was the placement test, which asses you before taking any lessons. This then sets your level based on your score, which saves you from having to go through all the basic levels (if you are more advanced).
I would recommend this to teachers, learners and designers. Have a look and you'll see why it in 2013, Apple chose Duolingo as its iPhone App of the Year, the first time this honour was awarded to an educational application. Duolingo has also won Best Education Start-up at the 2014 Crunchies.
I am not affiliated with this software in any way, I just like it!