Need to create a mobile app

Need to create an app that does the following : It would probably use some third party library or native libraries. I do not expect you to write the code for sound system itself :p (1) I produce a sound of 'X' frequency. - The app should tell me the frequency of the sound. (2) The app should be able to produce the sound of 'Y' frequency. - I can set the time in MIN and SEC for 'Y' frequency to be produced. - I can set multiple sounds of y1, y2, y3... frequencies to be produced for provided t1, t2, t3... times provided by user. - y1, y2, y3... are from a fixed set of frequencies provided by system. There is an initial screen(S0) that allows us to go to (S1) or (S2) (S1) is the first part which tells me the frequency of sound produced. When you go to (S2), you can select y1, y2, y3... and assign them with time(mm:ss) they need to produce sound with. You click start at this point. This takes you to screen three(S3) Here you simply print what frequency is playing currently. Budget around INR 800