Manipulate installed packages after the timer was set

I want to making an application that manipulating installed packages after the timer was set. After get list of installed apps using package manager, onListItemClick intent the timer class. So how can i manipulating installed apps after the timer(using alarm manager) was set on it? Thanks in advance.

`protected void onListItemClick(ListView l, View v, int position, long id) {
 super.onListItemClick(l, v, position, id);
 Intent i = new Intent(getApplicationContext(), timer.class);
 startActivity(i); }`

This is my timers class using alarm manager after intent by onListItemClick.

public void startAlert(View view) {
EditText text = (EditText) findViewById(R.id.time);
int i = Integer.parseInt(text.getText().toString());
Intent intent = new Intent(this, My.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this.getApplicationContext(), 0, intent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ (60 * i * 1000), pendingIntent);
Toast.makeText(this, "Timer set in " + i + " minutes",
Toast.LENGTH_LONG).show();}}