This application provides reference to about 968 ragas used in carnatic music that includes Melakarta (fundamental) and Janya (derived) ragas. The most interesting feature of this app is that you can search for a raga from its swaras (notes) and vice versa. It also provides the Arohanam (ascending scale) and Avarohanam (descending scale) of each raga.
Explore, learn and enjoy!
https://market.android.com/details?id=me.siva.carnaticragas&feature=search_result#?t=W251bGwsMSwxLDEsIm1lLnNpdmEuY2FybmF0aWNyYWdhcyJd