Gaana has a huge amount of Hindi music although you don't have to speak Hindi to use it. However, there are a few useful tips for newcomers to Hindi music to help you get the most out of Gaana. For example, The Mirchi Top 20 has the latest popular Hindi music with Tamil and Kannada top lists displaying popular regional music. In the Discover tab, under New Releases, you can filter music in up to 10 languages, which is useful for Indians from different regions.
There are Curated playlists based around popular holidays (such as Happy Lohri for the popular Punjabi winter holiday) or even around popular actors/actresses such as "Best of Neil Nitin Mukesh)". In addition there is a user generated list called "Old Hindi Songs" which is incredibly popular and for those that want to be on the cutting edge of Indian music, "Indipop" is the category for the latest Hindi beats.
Best of all, Gaana is for free. The only thing you have to put up with is adverts similar to the freemium model that Spotify is based on.
If you want free Hindi music and more on your mobile phone, Gaana is the perfect app.