Of course, there is Duolingo, which is a free (although there are premium services) way to learn many languages, including French, Japanese, German, Spanish, and even more of the most popular and beautiful languages.
There is also Memrise, which is similar to Duolingo, however I prefer Memrise, Yes, they have an app, and of course it is free with premium features (although not necessary).
Linguti.com is a site that I discovered recently that is AMAZING for learning new languages. It has a simple, easy to understand interface, and although focuses on Asian languages, does have more to offer.
The Pod101 company has a free site (with premium features) for most languages AND have a Youtube channel. However the Youtube channel for each language are chock full of learning whatever language you want, joining the site (again, for free) gives you access to podcasts you can listen to on the go through the "Inovative Language Learning" app (which is their app). To find the site/youtube channel simply look up "(desired language)Pod101".