Drawing over ImageView using finger touch , android

Question

Trying to develop an application where user can draw using their fingers over image view. Also what i want is user can change imageView image using button. So far i'm able to code for the image changing logic on click of next and previous buttons, can somebody please help me with the drawing part using the finger touch which user can clear on button click. Below is the code for so far i have worked on

public class MainActivity extends Activity {

    int images[] = { R.drawable.party1, R.drawable.party2, R.drawable.party3,
            R.drawable.party4, R.drawable.party5, R.drawable.party6,
            R.drawable.party7, R.drawable.party8, R.drawable.party9,
            R.drawable.party10 };
    ImageView hImageViewPic;
    Button btn_perv, btn_next;
    private int currentImage = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_next= (Button) findViewById(R.id.button_next);
        btn_perv = (Button) findViewById(R.id.button_previous);
        hImageViewPic = (ImageView) findViewById(R.id.imageView1);
        btn_next.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                currentImage++;
                currentImage = currentImage % images.length;

                hImageViewPic.setImageResource(images[currentImage]);
            }
        });

        btn_perv.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                 currentImage--;
                    currentImage = (currentImage + images.length) % images.length;

                    hImageViewPic.setImageResource(images[currentImage]);
            }
        });

    }
}