start

   playButton.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        //Enter intended consequences of clicking on playButton ImageView here
                        Log.v("Test: ", "Positive");

                        CountDownTimer countDownTimer = new CountDownTimer(100000, 100) {
                            @Override
                            public void onTick(long millisUntilFinished) {
                                TextView textView = (TextView) findViewById(R.id.main_timer_text);
                                textView.setText("Current Time: " + (millisUntilFinished / 1000) + " Seconds");

                            }

                            @Override
                            public void onFinish() {

                            }
                        }

                        .start();